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5 dayslib/scatterlist: fix temp buffer in extract_user_to_sg()Christian A. Ehrhardt1-2/+1
commit 118cf3f55975352ac357fb194405031458186819 upstream. Instead of allocating a temporary buffer for extracted user pages extract_user_to_sg() uses the end of the to be filled scatterlist as a temporary buffer. Fix the calculation of the start address if the scatterlist already contains elements. The unused space starts at sgtable->sgl + sgtable->nents not directly at sgtable->nents and the temporary buffer is placed at the end of this unused space. A subsequent commit will add kunit test cases that demonstrate that the patch is necessary. Pointed out by sashiko.dev on a previous iteration of this series. Link: https://lkml.kernel.org/r/20260326214905.818170-3-lk@c--e.de Fixes: 018584697533 ("netfs: Add a function to extract an iterator into a scatterlist") Signed-off-by: Christian A. Ehrhardt <lk@c--e.de> Cc: David Howells <dhowells@redhat.com> Cc: David Gow <davidgow@google.com> Cc: Kees Cook <kees@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: <stable@vger.kernel.org> [v6.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 dayslib/scatterlist: fix length calculations in extract_kvec_to_sgChristian A. Ehrhardt1-2/+3
commit 07b7d66e65d9cfe6b9c2c34aa22cfcaac37a5c45 upstream. Patch series "Fix bugs in extract_iter_to_sg()", v3. Fix bugs in the kvec and user variants of extract_iter_to_sg. This series is growing due to useful remarks made by sashiko.dev. The main bugs are: - The length for an sglist entry when extracting from a kvec can exceed the number of bytes in the page. This is obviously not intended. - When extracting a user buffer the sglist is temporarily used as a scratch buffer for extracted page pointers. If the sglist already contains some elements this scratch buffer could overlap with existing entries in the sglist. The series adds test cases to the kunit_iov_iter test that demonstrate all of these bugs. Additionally, there is a memory leak fix for the test itself. The bugs were orignally introduced into kernel v6.3 where the function lived in fs/netfs/iterator.c. It was later moved to lib/scatterlist.c in v6.5. Thus the actual fix is only marked for backports to v6.5+. This patch (of 5): When extracting from a kvec to a scatterlist, do not cross page boundaries. The required length was already calculated but not used as intended. Adjust the copied length if the loop runs out of sglist entries without extracting everything. While there, return immediately from extract_iter_to_sg if there are no sglist entries at all. A subsequent commit will add kunit test cases that demonstrate that the patch is necessary. Link: https://lkml.kernel.org/r/20260326214905.818170-1-lk@c--e.de Link: https://lkml.kernel.org/r/20260326214905.818170-2-lk@c--e.de Fixes: 018584697533 ("netfs: Add a function to extract an iterator into a scatterlist") Signed-off-by: Christian A. Ehrhardt <lk@c--e.de> Cc: David Gow <davidgow@google.com> Cc: David Howells <dhowells@redhat.com> Cc: Kees Cook <kees@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: <stable@vger.kernel.org> [v6.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 dayslib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()Lukas Wunner1-1/+1
commit 8c2f1288250a90a4b5cabed5d888d7e3aeed4035 upstream. Yiming reports an integer underflow in mpi_read_raw_from_sgl() when subtracting "lzeros" from the unsigned "nbytes". For this to happen, the scatterlist "sgl" needs to occupy more bytes than the "nbytes" parameter and the first "nbytes + 1" bytes of the scatterlist must be zero. Under these conditions, the while loop iterating over the scatterlist will count more zeroes than "nbytes", subtract the number of zeroes from "nbytes" and cause the underflow. When commit 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") originally introduced the bug, it couldn't be triggered because all callers of mpi_read_raw_from_sgl() passed a scatterlist whose length was equal to "nbytes". However since commit 63ba4d67594a ("KEYS: asymmetric: Use new crypto interface without scatterlists"), the underflow can now actually be triggered. When invoking a KEYCTL_PKEY_ENCRYPT system call with a larger "out_len" than "in_len" and filling the "in" buffer with zeroes, crypto_akcipher_sync_prep() will create an all-zero scatterlist used for both the "src" and "dst" member of struct akcipher_request and thereby fulfil the conditions to trigger the bug: sys_keyctl() keyctl_pkey_e_d_s() asymmetric_key_eds_op() software_key_eds_op() crypto_akcipher_sync_encrypt() crypto_akcipher_sync_prep() crypto_akcipher_encrypt() rsa_enc() mpi_read_raw_from_sgl() To the user this will be visible as a DoS as the kernel spins forever, causing soft lockup splats as a side effect. Fix it. Reported-by: Yiming Qian <yimingqian591@gmail.com> # off-list Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v4.4+ Reviewed-by: Ignat Korchagin <ignat@linux.win> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Link: https://lore.kernel.org/r/59eca92ff4f87e2081777f1423a0efaaadcfdb39.1776003111.git.lukas@wunner.de Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 dayslib: test_hmm: evict device pages on file close to avoid use-after-freeAlistair Popple1-37/+49
[ Upstream commit 744dd97752ef1076a8d8672bb0d8aa2c7abc1144 ] Patch series "Minor hmm_test fixes and cleanups". Two bugfixes a cleanup for the HMM kernel selftests. These were mostly reported by Zenghui Yu with special thanks to Lorenzo for analysing and pointing out the problems. This patch (of 3): When dmirror_fops_release() is called it frees the dmirror struct but doesn't migrate device private pages back to system memory first. This leaves those pages with a dangling zone_device_data pointer to the freed dmirror. If a subsequent fault occurs on those pages (eg. during coredump) the dmirror_devmem_fault() callback dereferences the stale pointer causing a kernel panic. This was reported [1] when running mm/ksft_hmm.sh on arm64, where a test failure triggered SIGABRT and the resulting coredump walked the VMAs faulting in the stale device private pages. Fix this by calling dmirror_device_evict_chunk() for each devmem chunk in dmirror_fops_release() to migrate all device private pages back to system memory before freeing the dmirror struct. The function is moved earlier in the file to avoid a forward declaration. Link: https://lore.kernel.org/20260331063445.3551404-1-apopple@nvidia.com Link: https://lore.kernel.org/20260331063445.3551404-2-apopple@nvidia.com Fixes: b2ef9f5a5cb3 ("mm/hmm/test: add selftest driver for HMM") Signed-off-by: Alistair Popple <apopple@nvidia.com> Reported-by: Zenghui Yu <zenghui.yu@linux.dev> Closes: https://lore.kernel.org/linux-mm/8bd0396a-8997-4d2e-a13f-5aac033083d7@linux.dev/ Reviewed-by: Balbir Singh <balbirs@nvidia.com> Tested-by: Zenghui Yu <zenghui.yu@linux.dev> Cc: David Hildenbrand <david@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zenghui Yu <zenghui.yu@linux.dev> Cc: Matthew Brost <matthew.brost@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ kept the existing simpler `dmirror_device_evict_chunk()` body instead of the upstream compound-folio version ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 dayslib/ts_kmp: fix integer overflow in pattern length calculationJosh Law1-2/+16
commit 8cdf30813ea8ce881cecc08664144416dbdb3e16 upstream. The ts_kmp algorithm stores its prefix_tbl[] table and pattern in a single allocation sized from the pattern length. If the prefix_tbl[] size calculation wraps, the resulting allocation can be too small and subsequent pattern copies can overflow it. Fix this by rejecting zero-length patterns and by using overflow helpers before calculating the combined allocation size. This fixes a potential heap overflow. The pattern length calculation can wrap during a size_t addition, leading to an undersized allocation. Because the textsearch library is reachable from userspace via Netfilter's xt_string module, this is a security risk that should be backported to LTS kernels. Link: https://lkml.kernel.org/r/20260308202028.2889285-2-objecting@objecting.org Signed-off-by: Josh Law <objecting@objecting.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-22x86-64/arm64/powerpc: clean up and rename __copy_from_user_flushcacheLinus Torvalds1-1/+1
commit 809b997a5ce945ab470f70c187048fe4f5df20bf upstream. This finishes the work on these odd functions that were only implemented by a handful of architectures. The 'flushcache' function was only used from the iterator code, and let's make it do the same thing that the nontemporal version does: remove the two underscores and add the user address checking. Yes, yes, the user address checking is also done at iovec import time, but we have long since walked away from the old double-underscore thing where we try to avoid address checking overhead at access time, and these functions shouldn't be so special and old-fashioned. The arm64 version already did the address check, in fact, so there it's just a matter of renaming it. For powerpc and x86-64 we now do the proper user access boilerplate. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-22x86: rename and clean up __copy_from_user_inatomic_nocache()Linus Torvalds1-1/+1
commit 5de7bcaadf160c1716b20a263cf8f5b06f658959 upstream. Similarly to the previous commit, this renames the somewhat confusingly named function. But in this case, it was at least less confusing: the __copy_from_user_inatomic_nocache is indeed copying from user memory, and it is indeed ok to be used in an atomic context, so it will not warn about it. But the previous commit also removed the NTB mis-use of the __copy_from_user_inatomic_nocache() function, and as a result every call-site is now _actually_ doing a real user copy. That means that we can now do the proper user pointer verification too. End result: add proper address checking, remove the double underscores, and change the "nocache" to "nontemporal" to more accurately describe what this x86-only function actually does. It might be worth noting that only the target is non-temporal: the actual user accesses are normal memory accesses. Also worth noting is that non-x86 targets (and on older 32-bit x86 CPU's before XMM2 in the Pentium III) we end up just falling back on a regular user copy, so nothing can actually depend on the non-temporal semantics, but that has always been true. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-18lib/crypto: chacha: Zeroize permuted_state before it leaves scopeEric Biggers1-0/+4
commit e5046823f8fa3677341b541a25af2fcb99a5b1e0 upstream. Since the ChaCha permutation is invertible, the local variable 'permuted_state' is sufficient to compute the original 'state', and thus the key, even after the permutation has been done. While the kernel is quite inconsistent about zeroizing secrets on the stack (and some prominent userspace crypto libraries don't bother at all since it's not guaranteed to work anyway), the kernel does try to do it as a best practice, especially in cases involving the RNG. Thus, explicitly zeroize 'permuted_state' before it goes out of scope. Fixes: c08d0e647305 ("crypto: chacha20 - Add a generic ChaCha20 stream cipher implementation") Cc: stable@vger.kernel.org Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260326032920.39408-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-25lib/bootconfig: check xbc_init_node() return in override pathJosh Law1-1/+2
[ Upstream commit bb288d7d869e86d382f35a0e26242c5ccb05ca82 ] The ':=' override path in xbc_parse_kv() calls xbc_init_node() to re-initialize an existing value node but does not check the return value. If xbc_init_node() fails (data offset out of range), parsing silently continues with stale node data. Add the missing error check to match the xbc_add_node() call path which already checks for failure. In practice, a bootconfig using ':=' to override a value near the 32KB data limit could silently retain the old value, meaning a security-relevant boot parameter override (e.g., a trace filter or debug setting) would not take effect as intended. Link: https://lore.kernel.org/all/20260318155847.78065-2-objecting@objecting.org/ Fixes: e5efaeb8a8f5 ("bootconfig: Support mixing a value and subkeys under a key") Signed-off-by: Josh Law <objecting@objecting.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-25lib/bootconfig: check bounds before writing in __xbc_open_brace()Josh Law1-1/+1
commit 560f763baa0f2c9a44da4294c06af071405ac46f upstream. The bounds check for brace_index happens after the array write. While the current call pattern prevents an actual out-of-bounds access (the previous call would have returned an error), the write-before-check pattern is fragile and would become a real out-of-bounds write if the error return were ever not propagated. Move the bounds check before the array write so the function is self-contained and safe regardless of caller behavior. Link: https://lore.kernel.org/all/20260312191143.28719-3-objecting@objecting.org/ Fixes: ead1e19ad905 ("lib/bootconfig: Fix a bug of breaking existing tree nodes") Cc: stable@vger.kernel.org Signed-off-by: Josh Law <objecting@objecting.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-25lib/bootconfig: fix snprintf truncation check in xbc_node_compose_key_after()Josh Law1-1/+1
commit 1120a36bb1e9b9e22de75ecb4ef0b998f73a97f1 upstream. snprintf() returns the number of characters that would have been written excluding the NUL terminator. Output is truncated when the return value is >= the buffer size, not just > the buffer size. When ret == size, the current code takes the non-truncated path, advancing buf by ret and reducing size to 0. This is wrong because the output was actually truncated (the last character was replaced by NUL). Fix by using >= so the truncation path is taken correctly. Link: https://lore.kernel.org/all/20260312191143.28719-4-objecting@objecting.org/ Fixes: 76db5a27a827 ("bootconfig: Add Extra Boot Config support") Cc: stable@vger.kernel.org Signed-off-by: Josh Law <objecting@objecting.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-25lib/bootconfig: fix off-by-one in xbc_verify_tree() unclosed brace errorJosh Law1-1/+1
commit 39ebc8d7f561e1b64eca87353ef9b18e2825e591 upstream. __xbc_open_brace() pushes entries with post-increment (open_brace[brace_index++]), so brace_index always points one past the last valid entry. xbc_verify_tree() reads open_brace[brace_index] to report which brace is unclosed, but this is one past the last pushed entry and contains stale/zero data, causing the error message to reference the wrong node. Use open_brace[brace_index - 1] to correctly identify the unclosed brace. brace_index is known to be > 0 here since we are inside the if (brace_index) guard. Link: https://lore.kernel.org/all/20260312191143.28719-2-objecting@objecting.org/ Fixes: ead1e19ad905 ("lib/bootconfig: Fix a bug of breaking existing tree nodes") Cc: stable@vger.kernel.org Signed-off-by: Josh Law <objecting@objecting.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-04Remove WARN_ALL_UNSEEDED_RANDOM kernel config optionLinus Torvalds1-27/+0
[ Upstream commit 7dff99b354601dd01829e1511711846e04340a69 ] This config option goes way back - it used to be an internal debug option to random.c (at that point called DEBUG_RANDOM_BOOT), then was renamed and exposed as a config option as CONFIG_WARN_UNSEEDED_RANDOM, and then further renamed to the current CONFIG_WARN_ALL_UNSEEDED_RANDOM. It was all done with the best of intentions: the more limited rate-limited reports were reporting some cases, but if you wanted to see all the gory details, you'd enable this "ALL" option. However, it turns out - perhaps not surprisingly - that when people don't care about and fix the first rate-limited cases, they most certainly don't care about any others either, and so warning about all of them isn't actually helping anything. And the non-ratelimited reporting causes problems, where well-meaning people enable debug options, but the excessive flood of messages that nobody cares about will hide actual real information when things go wrong. I just got a kernel bug report (which had nothing to do with randomness) where two thirds of the the truncated dmesg was just variations of random: get_random_u32 called from __get_random_u32_below+0x10/0x70 with crng_init=0 and in the process early boot messages had been lost (in addition to making the messages that _hadn't_ been lost harder to read). The proper way to find these things for the hypothetical developer that cares - if such a person exists - is almost certainly with boot time tracing. That gives you the option to get call graphs etc too, which is likely a requirement for fixing any problems anyway. See Documentation/trace/boottime-trace.rst for that option. And if we for some reason do want to re-introduce actual printing of these things, it will need to have some uniqueness filtering rather than this "just print it all" model. Fixes: cc1e127bfa95 ("random: remove ratelimiting for in-kernel unseeded randomness") Acked-by: Jason Donenfeld <Jason@zx2c4.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04objpool: fix the overestimation of object pooling metadata sizezhouwenhao1-1/+1
[ Upstream commit 5ed4b6b37c647d168ae31035b3f61b705997e043 ] objpool uses struct objpool_head to store metadata information, and its cpu_slots member points to an array of pointers that store the addresses of the percpu ring arrays. However, the memory size allocated during the initialization of cpu_slots is nr_cpu_ids * sizeof(struct objpool_slot). On a 64-bit machine, the size of struct objpool_slot is 16 bytes, which is twice the size of the actual pointer required, and the extra memory is never be used, resulting in a waste of memory. Therefore, the memory size required for cpu_slots needs to be corrected. Link: https://lkml.kernel.org/r/20260202132846.68257-1-zhouwenhao7600@gmail.com Fixes: b4edb8d2d464 ("lib: objpool added: ring-array based lockless MPMC") Signed-off-by: zhouwenhao <zhouwenhao7600@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matt Wu <wuqiang.matt@bytedance.com> Cc: wuqiang.matt <wuqiang.matt@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-11procfs: avoid fetching build ID while holding VMA lockAndrii Nakryiko1-12/+30
[ Upstream commit b5cbacd7f86f4f62b8813688c8e73be94e8e1951 ] Fix PROCMAP_QUERY to fetch optional build ID only after dropping mmap_lock or per-VMA lock, whichever was used to lock VMA under question, to avoid deadlock reported by syzbot: -> #1 (&mm->mmap_lock){++++}-{4:4}: __might_fault+0xed/0x170 _copy_to_iter+0x118/0x1720 copy_page_to_iter+0x12d/0x1e0 filemap_read+0x720/0x10a0 blkdev_read_iter+0x2b5/0x4e0 vfs_read+0x7f4/0xae0 ksys_read+0x12a/0x250 do_syscall_64+0xcb/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sb->s_type->i_mutex_key#8){++++}-{4:4}: __lock_acquire+0x1509/0x26d0 lock_acquire+0x185/0x340 down_read+0x98/0x490 blkdev_read_iter+0x2a7/0x4e0 __kernel_read+0x39a/0xa90 freader_fetch+0x1d5/0xa80 __build_id_parse.isra.0+0xea/0x6a0 do_procmap_query+0xd75/0x1050 procfs_procmap_ioctl+0x7a/0xb0 __x64_sys_ioctl+0x18e/0x210 do_syscall_64+0xcb/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&mm->mmap_lock); lock(&sb->s_type->i_mutex_key#8); lock(&mm->mmap_lock); rlock(&sb->s_type->i_mutex_key#8); *** DEADLOCK *** This seems to be exacerbated (as we haven't seen these syzbot reports before that) by the recent: 777a8560fd29 ("lib/buildid: use __kernel_read() for sleepable context") To make this safe, we need to grab file refcount while VMA is still locked, but other than that everything is pretty straightforward. Internal build_id_parse() API assumes VMA is passed, but it only needs the underlying file reference, so just add another variant build_id_parse_file() that expects file passed directly. [akpm@linux-foundation.org: fix up kerneldoc] Link: https://lkml.kernel.org/r/20260129215340.3742283-1-andrii@kernel.org Fixes: ed5d583a88a9 ("fs/procfs: implement efficient VMA querying API for /proc/<pid>/maps") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reported-by: <syzbot+4e70c8e0a2017b432f7a@syzkaller.appspotmail.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Yonghong Song <yonghong.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mm is local var instead of function param ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-06flex_proportions: make fprop_new_period() hardirq safeJan Kara1-2/+3
commit dd9e2f5b38f1fdd49b1ab6d3a85f81c14369eacc upstream. Bernd has reported a lockdep splat from flexible proportions code that is essentially complaining about the following race: <timer fires> run_timer_softirq - we are in softirq context call_timer_fn writeout_period fprop_new_period write_seqcount_begin(&p->sequence); <hardirq is raised> ... blk_mq_end_request() blk_update_request() ext4_end_bio() folio_end_writeback() __wb_writeout_add() __fprop_add_percpu_max() if (unlikely(max_frac < FPROP_FRAC_BASE)) { fprop_fraction_percpu() seq = read_seqcount_begin(&p->sequence); - sees odd sequence so loops indefinitely Note that a deadlock like this is only possible if the bdi has configured maximum fraction of writeout throughput which is very rare in general but frequent for example for FUSE bdis. To fix this problem we have to make sure write section of the sequence counter is irqsafe. Link: https://lkml.kernel.org/r/20260121112729.24463-2-jack@suse.cz Fixes: a91befde3503 ("lib/flex_proportions.c: remove local_irq_ops in fprop_new_period()") Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Bernd Schubert <bernd@bsbernd.com> Link: https://lore.kernel.org/all/9b845a47-9aee-43dd-99bc-1a82bea00442@bsbernd.com/ Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Joanne Koong <joannelkoong@gmail.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-23lib/buildid: use __kernel_read() for sleepable contextShakeel Butt1-12/+20
commit 777a8560fd29738350c5094d4166fe5499452409 upstream. Prevent a "BUG: unable to handle kernel NULL pointer dereference in filemap_read_folio". For the sleepable context, convert freader to use __kernel_read() instead of direct page cache access via read_cache_folio(). This simplifies the faultable code path by using the standard kernel file reading interface which handles all the complexity of reading file data. At the moment we are not changing the code for non-sleepable context which uses filemap_get_folio() and only succeeds if the target folios are already in memory and up-to-date. The reason is to keep the patch simple and easier to backport to stable kernels. Syzbot repro does not crash the kernel anymore and the selftests run successfully. In the follow up we will make __kernel_read() with IOCB_NOWAIT work for non-sleepable contexts. In addition, I would like to replace the secretmem check with a more generic approach and will add fstest for the buildid code. Link: https://lkml.kernel.org/r/20251222205859.3968077-1-shakeel.butt@linux.dev Fixes: ad41251c290d ("lib/buildid: implement sleepable build_id_parse() API") Reported-by: syzbot+09b7d050e4806540153d@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=09b7d050e4806540153d Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Jinchao Wang <wangjinchao600@gmail.com> Link: https://lkml.kernel.org/r/aUteBPWPYzVWIZFH@ndev Reviewed-by: Christian Brauner <brauner@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17lib/crypto: aes: Fix missing MMU protection for AES S-boxEric Biggers1-2/+2
commit 74d74bb78aeccc9edc10db216d6be121cf7ec176 upstream. __cacheline_aligned puts the data in the ".data..cacheline_aligned" section, which isn't marked read-only i.e. it doesn't receive MMU protection. Replace it with ____cacheline_aligned which does the right thing and just aligns the data while keeping it in ".rodata". Fixes: b5e0b032b6c3 ("crypto: aes - add generic time invariant AES cipher") Cc: stable@vger.kernel.org Reported-by: Qingfang Deng <dqfext@gmail.com> Closes: https://lore.kernel.org/r/20260105074712.498-1-dqfext@gmail.com/ Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260107052023.174620-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08idr: fix idr_alloc() returning an ID out of rangeMatthew Wilcox (Oracle)1-0/+2
commit c6e8e595a0798ad67da0f7bebaf69c31ef70dfff upstream. If you use an IDR with a non-zero base, and specify a range that lies entirely below the base, 'max - base' becomes very large and idr_get_free() can return an ID that lies outside of the requested range. Link: https://lkml.kernel.org/r/20251128161853.3200058-1-willy@infradead.org Fixes: 6ce711f27500 ("idr: Make 1-based IDRs more efficient") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reported-by: Jan Sokolowski <jan.sokolowski@intel.com> Reported-by: Koen Koning <koen.koning@intel.com> Reported-by: Peter Senna Tschudin <peter.senna@linux.intel.com> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6449 Reviewed-by: Christian König <christian.koenig@amd.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-18lib/vsprintf: Check pointer before dereferencing in time_and_date()Andy Shevchenko1-3/+3
[ Upstream commit 372a12bd5df0199aa234eaf8ef31ed7ecd61d40f ] The pointer may be invalid when gets to the printf(). In particular the time_and_date() dereferencing it in some cases without checking. Move the check from rtc_str() to time_and_date() to cover all cases. Fixes: 7daac5b2fdf8 ("lib/vsprintf: Print time64_t in human readable format") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://patch.msgid.link/20251110132118.4113976-1-andriy.shevchenko@linux.intel.com Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-01maple_tree: fix tracepoint string pointersMartin Kaiser1-14/+16
commit 91a54090026f84ceffaa12ac53c99b9f162946f6 upstream. maple_tree tracepoints contain pointers to function names. Such a pointer is saved when a tracepoint logs an event. There's no guarantee that it's still valid when the event is parsed later and the pointer is dereferenced. The kernel warns about these unsafe pointers. event 'ma_read' has unsafe pointer field 'fn' WARNING: kernel/trace/trace.c:3779 at ignore_event+0x1da/0x1e4 Mark the function names as tracepoint_string() to fix the events. One case that doesn't work without my patch would be trace-cmd record to save the binary ringbuffer and trace-cmd report to parse it in userspace. The address of __func__ can't be dereferenced from userspace but tracepoint_string will add an entry to /sys/kernel/tracing/printk_formats Link: https://lkml.kernel.org/r/20251030155537.87972-1-martin@kaiser.cx Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Martin Kaiser <martin@kaiser.cx> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13lib/crypto: curve25519-hacl64: Fix older clang KASAN workaround for GCCNathan Chancellor1-1/+1
commit 2b81082ad37cc3f28355fb73a6a69b91ff7dbf20 upstream. Commit 2f13daee2a72 ("lib/crypto/curve25519-hacl64: Disable KASAN with clang-17 and older") inadvertently disabled KASAN in curve25519-hacl64.o for GCC unconditionally because clang-min-version will always evaluate to nothing for GCC. Add a check for CONFIG_CC_IS_CLANG to avoid applying the workaround for GCC, which is only needed for clang-17 and older. Cc: stable@vger.kernel.org Fixes: 2f13daee2a72 ("lib/crypto/curve25519-hacl64: Disable KASAN with clang-17 and older") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20251103-curve25519-hacl64-fix-kasan-workaround-v2-1-ab581cbd8035@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13kunit: test_dev_action: Correctly cast 'priv' pointer to long*Florian Schmaus1-1/+1
[ Upstream commit 2551a1eedc09f5a86f94b038dc1bb16855c256f1 ] The previous implementation incorrectly assumed the original type of 'priv' was void**, leading to an unnecessary and misleading cast. Correct the cast of the 'priv' pointer in test_dev_action() to its actual type, long*, removing an unnecessary cast. As an additional benefit, this fixes an out-of-bounds CHERI fault on hardware with architectural capabilities. The original implementation tried to store a capability-sized pointer using the priv pointer. However, the priv pointer's capability only granted access to the memory region of its original long type, leading to a bounds violation since the size of a long is smaller than the size of a capability. This change ensures that the pointer usage respects the capabilities' bounds. Link: https://lore.kernel.org/r/20251017092814.80022-1-florian.schmaus@codasip.com Fixes: d03c720e03bd ("kunit: Add APIs for managing devices") Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Florian Schmaus <florian.schmaus@codasip.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-19lib/crypto/curve25519-hacl64: Disable KASAN with clang-17 and olderNathan Chancellor1-0/+4
commit 2f13daee2a72bb962f5fd356c3a263a6f16da965 upstream. After commit 6f110a5e4f99 ("Disable SLUB_TINY for build testing"), which causes CONFIG_KASAN to be enabled in allmodconfig again, arm64 allmodconfig builds with clang-17 and older show an instance of -Wframe-larger-than (which breaks the build with CONFIG_WERROR=y): lib/crypto/curve25519-hacl64.c:757:6: error: stack frame size (2336) exceeds limit (2048) in 'curve25519_generic' [-Werror,-Wframe-larger-than] 757 | void curve25519_generic(u8 mypublic[CURVE25519_KEY_SIZE], | ^ When KASAN is disabled, the stack usage is roughly quartered: lib/crypto/curve25519-hacl64.c:757:6: error: stack frame size (608) exceeds limit (128) in 'curve25519_generic' [-Werror,-Wframe-larger-than] 757 | void curve25519_generic(u8 mypublic[CURVE25519_KEY_SIZE], | ^ Using '-Rpass-analysis=stack-frame-layout' shows the following variables and many, many 8-byte spills when KASAN is enabled: Offset: [SP-144], Type: Variable, Align: 8, Size: 40 Offset: [SP-464], Type: Variable, Align: 8, Size: 320 Offset: [SP-784], Type: Variable, Align: 8, Size: 320 Offset: [SP-864], Type: Variable, Align: 32, Size: 80 Offset: [SP-896], Type: Variable, Align: 32, Size: 32 Offset: [SP-1016], Type: Variable, Align: 8, Size: 120 When KASAN is disabled, there are still spills but not at many and the variables list is smaller: Offset: [SP-192], Type: Variable, Align: 32, Size: 80 Offset: [SP-224], Type: Variable, Align: 32, Size: 32 Offset: [SP-344], Type: Variable, Align: 8, Size: 120 Disable KASAN for this file when using clang-17 or older to avoid blowing out the stack, clearing up the warning. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250609-curve25519-hacl64-disable-kasan-clang-v1-1-08ea0ac5ccff@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19lib/genalloc: fix device leak in of_gen_pool_get()Johan Hovold1-1/+4
commit 1260cbcffa608219fc9188a6cbe9c45a300ef8b5 upstream. Make sure to drop the reference taken when looking up the genpool platform device in of_gen_pool_get() before returning the pool. Note that holding a reference to a device does typically not prevent its devres managed resources from being released so there is no point in keeping the reference. Link: https://lkml.kernel.org/r/20250924080207.18006-1-johan@kernel.org Fixes: 9375db07adea ("genalloc: add devres support, allow to find a managed pool by device") Signed-off-by: Johan Hovold <johan@kernel.org> Cc: Philipp Zabel <p.zabel@pengutronix.de> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20lib/sbitmap: convert shallow_depth from one word to the whole sbitmapYu Kuai1-27/+29
[ Upstream commit 42e6c6ce03fd3e41e39a0f93f9b1a1d9fa664338 ] Currently elevators will record internal 'async_depth' to throttle asynchronous requests, and they both calculate shallow_dpeth based on sb->shift, with the respect that sb->shift is the available tags in one word. However, sb->shift is not the availbale tags in the last word, see __map_depth: if (index == sb->map_nr - 1) return sb->depth - (index << sb->shift); For consequence, if the last word is used, more tags can be get than expected, for example, assume nr_requests=256 and there are four words, in the worst case if user set nr_requests=32, then the first word is the last word, and still use bits per word, which is 64, to calculate async_depth is wrong. One the ohter hand, due to cgroup qos, bfq can allow only one request to be allocated, and set shallow_dpeth=1 will still allow the number of words request to be allocated. Fix this problems by using shallow_depth to the whole sbitmap instead of per word, also change kyber, mq-deadline and bfq to follow this, a new helper __map_depth_with_shallow() is introduced to calculate available bits in each word. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20250807032413.1469456-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-17lib/alloc_tag: do not acquire non-existent lock in alloc_tag_top_users()Harry Yoo1-0/+3
commit 99af22cd34688cc0d535a1919e0bea4cbc6c1ea1 upstream. alloc_tag_top_users() attempts to lock alloc_tag_cttype->mod_lock even when the alloc_tag_cttype is not allocated because: 1) alloc tagging is disabled because mem profiling is disabled (!alloc_tag_cttype) 2) alloc tagging is enabled, but not yet initialized (!alloc_tag_cttype) 3) alloc tagging is enabled, but failed initialization (!alloc_tag_cttype or IS_ERR(alloc_tag_cttype)) In all cases, alloc_tag_cttype is not allocated, and therefore alloc_tag_top_users() should not attempt to acquire the semaphore. This leads to a crash on memory allocation failure by attempting to acquire a non-existent semaphore: Oops: general protection fault, probably for non-canonical address 0xdffffc000000001b: 0000 [#3] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x00000000000000d8-0x00000000000000df] CPU: 2 UID: 0 PID: 1 Comm: systemd Tainted: G D 6.16.0-rc2 #1 VOLUNTARY Tainted: [D]=DIE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:down_read_trylock+0xaa/0x3b0 Code: d0 7c 08 84 d2 0f 85 a0 02 00 00 8b 0d df 31 dd 04 85 c9 75 29 48 b8 00 00 00 00 00 fc ff df 48 8d 6b 68 48 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 88 02 00 00 48 3b 5b 68 0f 85 53 01 00 00 65 ff RSP: 0000:ffff8881002ce9b8 EFLAGS: 00010016 RAX: dffffc0000000000 RBX: 0000000000000070 RCX: 0000000000000000 RDX: 000000000000001b RSI: 000000000000000a RDI: 0000000000000070 RBP: 00000000000000d8 R08: 0000000000000001 R09: ffffed107dde49d1 R10: ffff8883eef24e8b R11: ffff8881002cec20 R12: 1ffff11020059d37 R13: 00000000003fff7b R14: ffff8881002cec20 R15: dffffc0000000000 FS: 00007f963f21d940(0000) GS:ffff888458ca6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f963f5edf71 CR3: 000000010672c000 CR4: 0000000000350ef0 Call Trace: <TASK> codetag_trylock_module_list+0xd/0x20 alloc_tag_top_users+0x369/0x4b0 __show_mem+0x1cd/0x6e0 warn_alloc+0x2b1/0x390 __alloc_frozen_pages_noprof+0x12b9/0x21a0 alloc_pages_mpol+0x135/0x3e0 alloc_slab_page+0x82/0xe0 new_slab+0x212/0x240 ___slab_alloc+0x82a/0xe00 </TASK> As David Wang points out, this issue became easier to trigger after commit 780138b12381 ("alloc_tag: check mem_profiling_support in alloc_tag_init"). Before the commit, the issue occurred only when it failed to allocate and initialize alloc_tag_cttype or if a memory allocation fails before alloc_tag_init() is called. After the commit, it can be easily triggered when memory profiling is compiled but disabled at boot. To properly determine whether alloc_tag_init() has been called and its data structures initialized, verify that alloc_tag_cttype is a valid pointer before acquiring the semaphore. If the variable is NULL or an error value, it has not been properly initialized. In such a case, just skip and do not attempt to acquire the semaphore. [harry.yoo@oracle.com: v3] Link: https://lkml.kernel.org/r/20250624072513.84219-1-harry.yoo@oracle.com Link: https://lkml.kernel.org/r/20250620195305.1115151-1-harry.yoo@oracle.com Fixes: 780138b12381 ("alloc_tag: check mem_profiling_support in alloc_tag_init") Fixes: 1438d349d16b ("lib: add memory allocations report in show_mem()") Signed-off-by: Harry Yoo <harry.yoo@oracle.com> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202506181351.bba867dd-lkp@intel.com Acked-by: Suren Baghdasaryan <surenb@google.com> Tested-by: Raghavendra K T <raghavendra.kt@amd.com> Cc: Casey Chen <cachen@purestorage.com> Cc: David Wang <00107082@163.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Yuanyuan Zhong <yzhong@purestorage.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-17maple_tree: fix mt_destroy_walk() on root leaf nodeWei Yang1-0/+1
commit ea9b77f98d94c4d5c1bd1ac1db078f78b40e8bf5 upstream. On destroy, we should set each node dead. But current code miss this when the maple tree has only the root node. The reason is mt_destroy_walk() leverage mte_destroy_descend() to set node dead, but this is skipped since the only root node is a leaf. Fixes this by setting the node dead if it is a leaf. Link: https://lore.kernel.org/all/20250407231354.11771-1-richard.weiyang@gmail.com/ Link: https://lkml.kernel.org/r/20250624191841.64682-1-Liam.Howlett@oracle.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-10ubsan: integer-overflow: depend on BROKEN to keep this out of CIKees Cook1-0/+2
[ Upstream commit d6a0e0bfecccdcecb08defe75a137c7262352102 ] Depending on !COMPILE_TEST isn't sufficient to keep this feature out of CI because we can't stop it from being included in randconfig builds. This feature is still highly experimental, and is developed in lock-step with Clang's Overflow Behavior Types[1]. Depend on BROKEN to keep it from being enabled by anyone not expecting it. Link: https://discourse.llvm.org/t/rfc-v2-clang-introduce-overflowbehaviortypes-for-wrapping-and-non-wrapping-arithmetic/86507 [1] Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202505281024.f42beaa7-lkp@intel.com Fixes: 557f8c582a9b ("ubsan: Reintroduce signed overflow sanitizer") Acked-by: Eric Biggers <ebiggers@kernel.org> Link: https://lore.kernel.org/r/20250528182616.work.296-kees@kernel.org Reviewed-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Marco Elver <elver@google.com> Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10lib: test_objagg: Set error message in check_expect_hints_stats()Dan Carpenter1-1/+3
[ Upstream commit e6ed134a4ef592fe1fd0cafac9683813b3c8f3e8 ] Smatch complains that the error message isn't set in the caller: lib/test_objagg.c:923 test_hints_case2() error: uninitialized symbol 'errmsg'. This static checker warning only showed up after a recent refactoring but the bug dates back to when the code was originally added. This likely doesn't affect anything in real life. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/r/202506281403.DsuyHFTZ-lkp@intel.com/ Fixes: 0a020d416d0a ("lib: introduce initial implementation of object aggregation manager") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/8548f423-2e3b-4bb7-b816-5041de2762aa@sabinyo.mountain Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06maple_tree: fix MA_STATE_PREALLOC flag in mas_preallocate()Liam R. Howlett1-1/+3
commit fba46a5d83ca8decb338722fb4899026d8d9ead2 upstream. Temporarily clear the preallocation flag when explicitly requesting allocations. Pre-existing allocations are already counted against the request through mas_node_count_gfp(), but the allocations will not happen if the MA_STATE_PREALLOC flag is set. This flag is meant to avoid re-allocating in bulk allocation mode, and to detect issues with preallocation calculations. The MA_STATE_PREALLOC flag should also always be set on zero allocations so that detection of underflow allocations will print a WARN_ON() during consumption. User visible effect of this flaw is a WARN_ON() followed by a null pointer dereference when subsequent requests for larger number of nodes is ignored, such as the vma merge retry in mmap_region() caused by drivers altering the vma flags (which happens in v6.6, at least) Link: https://lkml.kernel.org/r/20250616184521.3382795-3-Liam.Howlett@oracle.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reported-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> Reported-by: Hailong Liu <hailong.liu@oppo.com> Link: https://lore.kernel.org/all/1652f7eb-a51b-4fee-8058-c73af63bacd1@oppo.com/ Link: https://lore.kernel.org/all/20250428184058.1416274-1-Liam.Howlett@oracle.com/ Link: https://lore.kernel.org/all/20250429014754.1479118-1-Liam.Howlett@oracle.com/ Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Hailong Liu <hailong.liu@oppo.com> Cc: zhangpeng.00@bytedance.com <zhangpeng.00@bytedance.com> Cc: Steve Kang <Steve.Kang@unisoc.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-06lib/group_cpus: fix NULL pointer dereference from group_cpus_evenly()Yu Kuai1-1/+8
commit df831e97739405ecbaddb85516bc7d4d1c933d6b upstream. While testing null_blk with configfs, echo 0 > poll_queues will trigger following panic: BUG: kernel NULL pointer dereference, address: 0000000000000010 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 27 UID: 0 PID: 920 Comm: bash Not tainted 6.15.0-02023-gadbdb95c8696-dirty #1238 PREEMPT(undef) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:__bitmap_or+0x48/0x70 Call Trace: <TASK> __group_cpus_evenly+0x822/0x8c0 group_cpus_evenly+0x2d9/0x490 blk_mq_map_queues+0x1e/0x110 null_map_queues+0xc9/0x170 [null_blk] blk_mq_update_queue_map+0xdb/0x160 blk_mq_update_nr_hw_queues+0x22b/0x560 nullb_update_nr_hw_queues+0x71/0xf0 [null_blk] nullb_device_poll_queues_store+0xa4/0x130 [null_blk] configfs_write_iter+0x109/0x1d0 vf