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7 daysbpf: reject direct access to nullable PTR_TO_BUF pointersQi Tang1-1/+2
[ Upstream commit b0db1accbc7395657c2b79db59fa9fae0d6656f3 ] check_mem_access() matches PTR_TO_BUF via base_type() which strips PTR_MAYBE_NULL, allowing direct dereference without a null check. Map iterator ctx->key and ctx->value are PTR_TO_BUF | PTR_MAYBE_NULL. On stop callbacks these are NULL, causing a kernel NULL dereference. Add a type_may_be_null() guard to the PTR_TO_BUF branch, matching the existing PTR_TO_BTF_ID pattern. Fixes: 20b2aff4bc15 ("bpf: Introduce MEM_RDONLY flag") Signed-off-by: Qi Tang <tpluszz77@gmail.com> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20260402092923.38357-2-tpluszz77@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
7 daysbpf: Fix regsafe() for pointers to packetAlexei Starovoitov1-1/+6
[ Upstream commit a8502a79e832b861e99218cbd2d8f4312d62e225 ] In case rold->reg->range == BEYOND_PKT_END && rcur->reg->range == N regsafe() may return true which may lead to current state with valid packet range not being explored. Fix the bug. Fixes: 6d94e741a8ff ("bpf: Support for pointers beyond pkt_end.") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Amery Hung <ameryhung@gmail.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20260331204228.26726-1-alexei.starovoitov@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
7 daysbpf: Release module BTF IDR before module unloadKumar Kartikeya Dwivedi1-4/+20
[ Upstream commit 146bd2a87a65aa407bb17fac70d8d583d19aba06 ] Gregory reported in [0] that the global_map_resize test when run in repeatedly ends up failing during program load. This stems from the fact that BTF reference has not dropped to zero after the previous run's module is unloaded, and the older module's BTF is still discoverable and visible. Later, in libbpf, load_module_btfs() will find the ID for this stale BTF, open its fd, and then it will be used during program load where later steps taking module reference using btf_try_get_module() fail since the underlying module for the BTF is gone. Logically, once a module is unloaded, it's associated BTF artifacts should become hidden. The BTF object inside the kernel may still remain alive as long its reference counts are alive, but it should no longer be discoverable. To fix this, let us call btf_free_id() from the MODULE_STATE_GOING case for the module unload to free the BTF associated IDR entry, and disable its discovery once module unload returns to user space. If a race happens during unload, the outcome is non-deterministic anyway. However, user space should be able to rely on the guarantee that once it has synchronously established a successful module unload, no more stale artifacts associated with this module can be obtained subsequently. Note that we must be careful to not invoke btf_free_id() in btf_put() when btf_is_module() is true now. There could be a window where the module unload drops a non-terminal reference, frees the IDR, but the same ID gets reused and the second unconditional btf_free_id() ends up releasing an unrelated entry. To avoid a special case for btf_is_module() case, set btf->id to zero to make btf_free_id() idempotent, such that we can unconditionally invoke it from btf_put(), and also from the MODULE_STATE_GOING case. Since zero is an invalid IDR, the idr_remove() should be a noop. Note that we can be sure that by the time we reach final btf_put() for btf_is_module() case, the btf_free_id() is already done, since the module itself holds the BTF reference, and it will call this function for the BTF before dropping its own reference. [0]: https://lore.kernel.org/bpf/cover.1773170190.git.grbell@redhat.com Fixes: 36e68442d1af ("bpf: Load and verify kernel module BTFs") Acked-by: Martin KaFai Lau <martin.lau@kernel.org> Suggested-by: Martin KaFai Lau <martin.lau@kernel.org> Reported-by: Gregory Bell <grbell@redhat.com> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20260312205307.1346991-1-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-25bpf: Forget ranges when refining tnum after JSETPaul Chaignon1-0/+4
commit 6279846b9b2532e1b04559ef8bd0dec049f29383 upstream. Syzbot reported a kernel warning due to a range invariant violation on the following BPF program. 0: call bpf_get_netns_cookie 1: if r0 == 0 goto <exit> 2: if r0 & Oxffffffff goto <exit> The issue is on the path where we fall through both jumps. That path is unreachable at runtime: after insn 1, we know r0 != 0, but with the sign extension on the jset, we would only fallthrough insn 2 if r0 == 0. Unfortunately, is_branch_taken() isn't currently able to figure this out, so the verifier walks all branches. The verifier then refines the register bounds using the second condition and we end up with inconsistent bounds on this unreachable path: 1: if r0 == 0 goto <exit> r0: u64=[0x1, 0xffffffffffffffff] var_off=(0, 0xffffffffffffffff) 2: if r0 & 0xffffffff goto <exit> r0 before reg_bounds_sync: u64=[0x1, 0xffffffffffffffff] var_off=(0, 0) r0 after reg_bounds_sync: u64=[0x1, 0] var_off=(0, 0) Improving the range refinement for JSET to cover all cases is tricky. We also don't expect many users to rely on JSET given LLVM doesn't generate those instructions. So instead of improving the range refinement for JSETs, Eduard suggested we forget the ranges whenever we're narrowing tnums after a JSET. This patch implements that approach. Reported-by: syzbot+c711ce17dd78e5d4fdcf@syzkaller.appspotmail.com Suggested-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com> Link: https://lore.kernel.org/r/9d4fd6432a095d281f815770608fdcd16028ce0b.1752171365.git.paul.chaignon@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> [ shung-hsi.yu: no detection or kernel warning for invariant violation before 6.8, but the same umin=1,umax=0 state can occur when jset is preceed by r0 < 1. Changes were made to adapt to older range refinement logic before commit 67420501e868 ("bpf: generalize reg_set_min_max() to handle non-const register comparisons"). ] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-25bpf: Fix a UAF issue in bpf_trampoline_link_cgroup_shimLang Xu1-3/+1
[ Upstream commit 56145d237385ca0e7ca9ff7b226aaf2eb8ef368b ] The root cause of this bug is that when 'bpf_link_put' reduces the refcount of 'shim_link->link.link' to zero, the resource is considered released but may still be referenced via 'tr->progs_hlist' in 'cgroup_shim_find'. The actual cleanup of 'tr->progs_hlist' in 'bpf_shim_tramp_link_release' is deferred. During this window, another process can cause a use-after-free via 'bpf_trampoline_link_cgroup_shim'. Based on Martin KaFai Lau's suggestions, I have created a simple patch. To fix this: Add an atomic non-zero check in 'bpf_trampoline_link_cgroup_shim'. Only increment the refcount if it is not already zero. Testing: I verified the fix by adding a delay in 'bpf_shim_tramp_link_release' to make the bug easier to trigger: static void bpf_shim_tramp_link_release(struct bpf_link *link) { /* ... */ if (!shim_link->trampoline) return; + msleep(100); WARN_ON_ONCE(bpf_trampoline_unlink_prog(&shim_link->link, shim_link->trampoline, NULL)); bpf_trampoline_put(shim_link->trampoline); } Before the patch, running a PoC easily reproduced the crash(almost 100%) with a call trace similar to KaiyanM's report. After the patch, the bug no longer occurs even after millions of iterations. Fixes: 69fd337a975c ("bpf: per-cgroup lsm flavor") Reported-by: Kaiyan Mei <M202472210@hust.edu.cn> Closes: https://lore.kernel.org/bpf/3c4ebb0b.46ff8.19abab8abe2.Coremail.kaiyanm@hust.edu.cn/ Signed-off-by: Lang Xu <xulang@uniontech.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/279EEE1BA1DDB49D+20260303095217.34436-1-xulang@uniontech.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-25bpf: export bpf_link_inc_not_zero.Kui-Feng Lee1-1/+2
[ Upstream commit 67c3e8353f45c27800eecc46e00e8272f063f7d1 ] bpf_link_inc_not_zero() will be used by kernel modules. We will use it in bpf_testmod.c later. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240530065946.979330-5-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Stable-dep-of: 56145d237385 ("bpf: Fix a UAF issue in bpf_trampoline_link_cgroup_shim") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-25bpf: Fix stack-out-of-bounds write in devmapKohei Enju1-5/+17
[ Upstream commit b7bf516c3ecd9a2aae2dc2635178ab87b734fef1 ] get_upper_ifindexes() iterates over all upper devices and writes their indices into an array without checking bounds. Also the callers assume that the max number of upper devices is MAX_NEST_DEV and allocate excluded_devices[1+MAX_NEST_DEV] on the stack, but that assumption is not correct and the number of upper devices could be larger than MAX_NEST_DEV (e.g., many macvlans), causing a stack-out-of-bounds write. Add a max parameter to get_upper_ifindexes() to avoid the issue. When there are too many upper devices, return -EOVERFLOW and abort the redirect. To reproduce, create more than MAX_NEST_DEV(8) macvlans on a device with an XDP program attached using BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS. Then send a packet to the device to trigger the XDP redirect path. Reported-by: syzbot+10cc7f13760b31bd2e61@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/698c4ce3.050a0220.340abe.000b.GAE@google.com/T/ Fixes: aeea1b86f936 ("bpf, devmap: Exclude XDP broadcast to master device") Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Kohei Enju <kohei@enjuk.jp> Link: https://lore.kernel.org/r/20260225053506.4738-1-kohei@enjuk.jp Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04bpf: verifier improvement in 32bit shift sign extension patternCupertino Miranda1-11/+7
[ Upstream commit d18dec4b8990048ce75f0ece32bb96b3fbd3f422 ] This patch improves the verifier to correctly compute bounds for sign extension compiler pattern composed of left shift by 32bits followed by a sign right shift by 32bits. Pattern in the verifier was limitted to positive value bounds and would reset bound computation for negative values. New code allows both positive and negative values for sign extension without compromising bound computation and verifier to pass. This change is required by GCC which generate such pattern, and was detected in the context of systemd, as described in the following GCC bugzilla: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119731 Three new tests were added in verifier_subreg.c. Signed-off-by: Cupertino Miranda <cupertino.miranda@oracle.com> Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Cc: David Faust <david.faust@oracle.com> Cc: Jose Marchesi <jose.marchesi@oracle.com> Cc: Elena Zannoni <elena.zannoni@oracle.com> Link: https://lore.kernel.org/r/20251202180220.11128-2-cupertino.miranda@oracle.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-06bpf: Reject narrower access to pointer ctx fieldsPaul Chaignon1-4/+4
commit e09299225d5ba3916c91ef70565f7d2187e4cca0 upstream. The following BPF program, simplified from a syzkaller repro, causes a kernel warning: r0 = *(u8 *)(r1 + 169); exit; With pointer field sk being at offset 168 in __sk_buff. This access is detected as a narrower read in bpf_skb_is_valid_access because it doesn't match offsetof(struct __sk_buff, sk). It is therefore allowed and later proceeds to bpf_convert_ctx_access. Note that for the "is_narrower_load" case in the convert_ctx_accesses(), the insn->off is aligned, so the cnt may not be 0 because it matches the offsetof(struct __sk_buff, sk) in the bpf_convert_ctx_access. However, the target_size stays 0 and the verifier errors with a kernel warning: verifier bug: error during ctx access conversion(1) This patch fixes that to return a proper "invalid bpf_context access off=X size=Y" error on the load instruction. The same issue affects multiple other fields in context structures that allow narrow access. Some other non-affected fields (for sk_msg, sk_lookup, and sockopt) were also changed to use bpf_ctx_range_ptr for consistency. Note this syzkaller crash was reported in the "Closes" link below, which used to be about a different bug, fixed in commit fce7bd8e385a ("bpf/verifier: Handle BPF_LOAD_ACQ instructions in insn_def_regno()"). Because syzbot somehow confused the two bugs, the new crash and repro didn't get reported to the mailing list. Fixes: f96da09473b52 ("bpf: simplify narrower ctx access") Fixes: 0df1a55afa832 ("bpf: Warn on internal verifier errors") Reported-by: syzbot+0ef84a7bdf5301d4cbec@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0ef84a7bdf5301d4cbec Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://patch.msgid.link/3b8dcee67ff4296903351a974ddd9c4dca768b64.1753194596.git.paul.chaignon@gmail.com [shung-hsi.yu: offset(struct bpf_sock_ops, skb_hwtstamp) case was dropped becasuse it was only added in v6.2 with commit 9bb053490f1a ("bpf: Add hwtstamp field for the sockops prog")] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11bpf: Fix invalid prog->stats access when update_effective_progs failsPu Lehui1-0/+3
[ Upstream commit 7dc211c1159d991db609bdf4b0fb9033c04adcbc ] Syzkaller triggers an invalid memory access issue following fault injection in update_effective_progs. The issue can be described as follows: __cgroup_bpf_detach update_effective_progs compute_effective_progs bpf_prog_array_alloc <-- fault inject purge_effective_progs /* change to dummy_bpf_prog */ array->items[index] = &dummy_bpf_prog.prog ---softirq start--- __do_softirq ... __cgroup_bpf_run_filter_skb __bpf_prog_run_save_cb bpf_prog_run stats = this_cpu_ptr(prog->stats) /* invalid memory access */ flags = u64_stats_update_begin_irqsave(&stats->syncp) ---softirq end--- static_branch_dec(&cgroup_bpf_enabled_key[atype]) The reason is that fault injection caused update_effective_progs to fail and then changed the original prog into dummy_bpf_prog.prog in purge_effective_progs. Then a softirq came, and accessing the members of dummy_bpf_prog.prog in the softirq triggers invalid mem access. To fix it, skip updating stats when stats is NULL. Fixes: 492ecee892c2 ("bpf: enable program stats") Signed-off-by: Pu Lehui <pulehui@huawei.com> Link: https://lore.kernel.org/r/20251115102343.2200727-1-pulehui@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-11bpf: Improve program stats run-time calculationJose Fernandez1-1/+2
[ Upstream commit ce09cbdd988887662546a1175bcfdfc6c8fdd150 ] This patch improves the run-time calculation for program stats by capturing the duration as soon as possible after the program returns. Previously, the duration included u64_stats_t operations. While the instrumentation overhead is part of the total time spent when stats are enabled, distinguishing between the program's native execution time and the time spent due to instrumentation is crucial for accurate performance analysis. By making this change, the patch facilitates more precise optimization of BPF programs, enabling users to understand their performance in environments without stats enabled. I used a virtualized environment to measure the run-time over one minute for a basic raw_tracepoint/sys_enter program, which just increments a local counter. Although the virtualization introduced some performance degradation that could affect the results, I observed approximately a 16% decrease in average run-time reported by stats with this change (310 -> 260 nsec). Signed-off-by: Jose Fernandez <josef@netflix.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240402034010.25060-1-josef@netflix.com Stable-dep-of: 7dc211c1159d ("bpf: Fix invalid prog->stats access when update_effective_progs fails") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-07bpf: Sync pending IRQ work before freeing ring bufferNoorain Eqbal1-0/+2
[ Upstream commit 4e9077638301816a7d73fa1e1b4c1db4a7e3b59c ] Fix a race where irq_work can be queued in bpf_ringbuf_commit() but the ring buffer is freed before the work executes. In the syzbot reproducer, a BPF program attached to sched_switch triggers bpf_ringbuf_commit(), queuing an irq_work. If the ring buffer is freed before this work executes, the irq_work thread may accesses freed memory. Calling `irq_work_sync(&rb->work)` ensures that all pending irq_work complete before freeing the buffer. Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Reported-by: syzbot+2617fc732430968b45d2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2617fc732430968b45d2 Tested-by: syzbot+2617fc732430968b45d2@syzkaller.appspotmail.com Signed-off-by: Noorain Eqbal <nooraineqbal@gmail.com> Link: https://lore.kernel.org/r/20251020180301.103366-1-nooraineqbal@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-19bpf: Avoid RCU context warning when unpinning htab with internal structsKaFai Wan1-2/+2
[ Upstream commit 4f375ade6aa9f37fd72d7a78682f639772089eed ] When unpinning a BPF hash table (htab or htab_lru) that contains internal structures (timer, workqueue, or task_work) in its values, a BUG warning is triggered: BUG: sleeping function called from invalid context at kernel/bpf/hashtab.c:244 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 14, name: ksoftirqd/0 ... The issue arises from the interaction between BPF object unpinning and RCU callback mechanisms: 1. BPF object unpinning uses ->free_inode() which schedules cleanup via call_rcu(), deferring the actual freeing to an RCU callback that executes within the RCU_SOFTIRQ context. 2. During cleanup of hash tables containing internal structures, htab_map_free_internal_structs() is invoked, which includes cond_resched() or cond_resched_rcu() calls to yield the CPU during potentially long operations. However, cond_resched() or cond_resched_rcu() cannot be safely called from atomic RCU softirq context, leading to the BUG warning when attempting to reschedule. Fix this by changing from ->free_inode() to ->destroy_inode() and rename bpf_free_inode() to bpf_destroy_inode() for BPF objects (prog, map, link). This allows direct inode freeing without RCU callback scheduling, avoiding the invalid context warning. Reported-by: Le Chen <tom2cat@sjtu.edu.cn> Closes: https://lore.kernel.org/all/1444123482.1827743.1750996347470.JavaMail.zimbra@sjtu.edu.cn/ Fixes: 68134668c17f ("bpf: Add map side support for bpf timers.") Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: KaFai Wan <kafai.wan@linux.dev> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20251008102628.808045-2-kafai.wan@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15bpf: Enforce expected_attach_type for tailcall compatibilityDaniel Borkmann1-0/+5
[ Upstream commit 4540aed51b12bc13364149bf95f6ecef013197c0 ] Yinhao et al. recently reported: Our fuzzer tool discovered an uninitialized pointer issue in the bpf_prog_test_run_xdp() function within the Linux kernel's BPF subsystem. This leads to a NULL pointer dereference when a BPF program attempts to deference the txq member of struct xdp_buff object. The test initializes two programs of BPF_PROG_TYPE_XDP: progA acts as the entry point for bpf_prog_test_run_xdp() and its expected_attach_type can neither be of be BPF_XDP_DEVMAP nor BPF_XDP_CPUMAP. progA calls into a slot of a tailcall map it owns. progB's expected_attach_type must be BPF_XDP_DEVMAP to pass xdp_is_valid_access() validation. The program returns struct xdp_md's egress_ifindex, and the latter is only allowed to be accessed under mentioned expected_attach_type. progB is then inserted into the tailcall which progA calls. The underlying issue goes beyond XDP though. Another example are programs of type BPF_PROG_TYPE_CGROUP_SOCK_ADDR. sock_addr_is_valid_access() as well as sock_addr_func_proto() have different logic depending on the programs' expected_attach_type. Similarly, a program attached to BPF_CGROUP_INET4_GETPEERNAME should not be allowed doing a tailcall into a program which calls bpf_bind() out of BPF which is only enabled for BPF_CGROUP_INET4_CONNECT. In short, specifying expected_attach_type allows to open up additional functionality or restrictions beyond what the basic bpf_prog_type enables. The use of tailcalls must not violate these constraints. Fix it by enforcing expected_attach_type in __bpf_prog_map_compatible(). Note that we only enforce this for tailcall maps, but not for BPF devmaps or cpumaps: There, the programs are invoked through dev_map_bpf_prog_run*() and cpu_map_bpf_prog_run*() which set up a new environment / context and therefore these situations are not prone to this issue. Fixes: 5e43f899b03a ("bpf: Check attach type at prog load time") Reported-by: Yinhao Hu <dddddd@hust.edu.cn> Reported-by: Kaiyan Mei <M202472210@hust.edu.cn> Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20250926171201.188490-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-02bpf: Reject bpf_timer for PREEMPT_RTLeon Hwang1-0/+4
[ Upstream commit e25ddfb388c8b7e5f20e3bf38d627fb485003781 ] When enable CONFIG_PREEMPT_RT, the kernel will warn when run timer selftests by './test_progs -t timer': BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 In order to avoid such warning, reject bpf_timer in verifier when PREEMPT_RT is enabled. Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Link: https://lore.kernel.org/r/20250910125740.52172-2-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-09bpf: Fix oob access in cgroup local storageDaniel Borkmann1-0/+15
[ Upstream commit abad3d0bad72a52137e0c350c59542d75ae4f513 ] Lonial reported that an out-of-bounds access in cgroup local storage can be crafted via tail calls. Given two programs each utilizing a cgroup local storage with a different value size, and one program doing a tail call into the other. The verifier will validate each of the indivial programs just fine. However, in the runtime context the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the BPF program as well as any cgroup local storage flavor the program uses. Helpers such as bpf_get_local_storage() pick this up from the runtime context: ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx); storage = ctx->prog_item->cgroup_storage[stype]; if (stype == BPF_CGROUP_STORAGE_SHARED) ptr = &READ_ONCE(storage->buf)->data[0]; else ptr = this_cpu_ptr(storage->percpu_buf); For the second program which was called from the originally attached one, this means bpf_get_local_storage() will pick up the former program's map, not its own. With mismatching sizes, this can result in an unintended out-of-bounds access. To fix this issue, we need to extend bpf_map_owner with an array of storage_cookie[] to match on i) the exact maps from the original program if the second program was using bpf_get_local_storage(), or ii) allow the tail call combination if the second program was not using any of the cgroup local storage maps. Fixes: 7d9c3427894f ("bpf: Make cgroup storages shared between programs on the same cgroup") Reported-by: Lonial Con <kongln9170@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20250730234733.530041-4-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-09bpf: Move bpf map owner out of common structDaniel Borkmann2-23/+25
[ Upstream commit fd1c98f0ef5cbcec842209776505d9e70d8fcd53 ] Given this is only relevant for BPF tail call maps, it is adding up space and penalizing other map types. We also need to extend this with further objects to track / compare to. Therefore, lets move this out into a separate structure and dynamically allocate it only for BPF tail call maps. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20250730234733.530041-2-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-09bpf: Add cookie object to bpf mapsDaniel Borkmann1-0/+6
[ Upstream commit 12df58ad294253ac1d8df0c9bb9cf726397a671d ] Add a cookie to BPF maps to uniquely identify BPF maps for the timespan when the node is up. This is different to comparing a pointer or BPF map id which could get rolled over and reused. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20250730234733.530041-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15bpf/preload: Don't select USERMODE_DRIVERThomas Weißschuh1-1/+0
[ Upstream commit 2b03164eee20eac7ce0fe3aa4fbda7efc1e5427a ] The usermode driver framework is not used anymore by the BPF preload code. Fixes: cb80ddc67152 ("bpf: Convert bpf_preload.ko to use light skeleton.") Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/bpf/20250721-remove-usermode-driver-v1-1-0d0083334382@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-24bpf: Reject %p% format string in bprintf-like helpersPaul Chaignon1-3/+8
[ Upstream commit f8242745871f81a3ac37f9f51853d12854fd0b58 ] static const char fmt[] = "%p%"; bpf_trace_printk(fmt, sizeof(fmt)); The above BPF program isn't rejected and causes a kernel warning at runtime: Please remove unsupported %\x00 in format string WARNING: CPU: 1 PID: 7244 at lib/vsprintf.c:2680 format_decode+0x49c/0x5d0 This happens because bpf_bprintf_prepare skips over the second %, detected as punctuation, while processing %p. This patch fixes it by not skipping over punctuation. %\x00 is then processed in the next iteration and rejected. Reported-by: syzbot+e2c932aec5c8a6e1d31c@syzkaller.appspotmail.com Fixes: 48cac3f4a96d ("bpf: Implement formatted output helpers with bstr_printf") Acked-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com> Link: https://lore.kernel.org/r/a0e06cc479faec9e802ae51ba5d66420523251ee.1751395489.git.paul.chaignon@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem()Hou Tao1-1/+2
[ Upstream commit d4965578267e2e81f67c86e2608481e77e9c8569 ] bpf_map_lookup_percpu_elem() helper is also available for sleepable bpf program. When BPF JIT is disabled or under 32-bit host, bpf_map_lookup_percpu_elem() will not be inlined. Using it in a sleepable bpf program will trigger the warning in bpf_map_lookup_percpu_elem(), because the bpf program only holds rcu_read_lock_trace lock. Therefore, add the missed check. Reported-by: syzbot+dce5aae19ae4d6399986@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/000000000000176a130617420310@google.com/ Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20250526062534.1105938-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27bpf: Avoid __bpf_prog_ret0_warn when jit failsKaFai Wan1-1/+1
[ Upstream commit 86bc9c742426a16b52a10ef61f5b721aecca2344 ] syzkaller reported an issue: WARNING: CPU: 3 PID: 217 at kernel/bpf/core.c:2357 __bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357 Modules linked in: CPU: 3 UID: 0 PID: 217 Comm: kworker/u32:6 Not tainted 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 RIP: 0010:__bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357 Call Trace: <TASK> bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] cls_bpf_classify+0x74a/0x1110 net/sched/cls_bpf.c:105 ... When creating bpf program, 'fp->jit_requested' depends on bpf_jit_enable. This issue is triggered because of CONFIG_BPF_JIT_ALWAYS_ON is not set and bpf_jit_enable is set to 1, causing the arch to attempt JIT the prog, but jit failed due to FAULT_INJECTION. As a result, incorrectly treats the program as valid, when the program runs it calls `__bpf_prog_ret0_warn` and triggers the WARN_ON_ONCE(1). Reported-by: syzbot+0903f6d7f285e41cdf10@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/6816e34e.a70a0220.254cdc.002c.GAE@google.com Fixes: fa9dd599b4da ("bpf: get rid of pure_initcall dependency to enable jits") Signed-off-by: KaFai Wan <mannkafai@gmail.com> Link: https://lore.kernel.org/r/20250526133358.2594176-1-mannkafai@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04bpf: Return prog btf_id without capable checkMykyta Yatsenko1-2/+2
[ Upstream commit 07651ccda9ff10a8ca427670cdd06ce2c8e4269c ] Return prog's btf_id from bpf_prog_get_info_by_fd regardless of capable check. This patch enables scenario, when freplace program, running from user namespace, requires to query target prog's btf. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20250317174039.161275-3-mykyta.yatsenko5@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04bpf: fix possible endless loop in BPF map iterationBrandon Kammerdiener1-1/+1
[ Upstream commit 75673fda0c557ae26078177dd14d4857afbf128d ] The _safe variant used here gets the next element before running the callback, avoiding the endless loop condition. Signed-off-by: Brandon Kammerdiener <brandon.kammerdiener@intel.com> Link: https://lore.kernel.org/r/20250424153246.141677-2-brandon.kammerdiener@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-25bpf: Prevent tail call between progs attached to different hooksXu Kuohai1-2/+17
commit 28ead3eaabc16ecc907cfb71876da028080f6356 upstream. bpf progs can be attached to kernel functions, and the attached functions can take different parameters or return different return values. If prog attached to one kernel function tail calls prog attached to another kernel function, the ctx access or return value verification could be bypassed. For example, if prog1 is attached to func1 which takes only 1 parameter and prog2 is attached to func2 which takes two parameters. Since verifier assumes the bpf ctx passed to prog2 is constructed based on func2's prototype, verifier allows prog2 to access the second parameter from the bpf ctx passed to it. The problem is that verifier does not prevent prog1 from passing its bpf ctx to prog2 via tail call. In this case, the bpf ctx passed to prog2 is constructed from func1 instead of func2, that is, the assumption for ctx access verification is bypassed. Another example, if BPF LSM prog1 is attached to hook file_alloc_security, and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier knows the return value rules for these two hooks, e.g. it is legal for bpf_lsm_audit_rule_known to return positive number 1, and it is illegal for file_alloc_security to return positive number. So verifier allows prog2 to return positive number 1, but does not allow prog1 to return positive number. The problem is that verifier does not prevent prog1 from calling prog2 via tail call. In this case, prog2's return value 1 will be used as the return value for prog1's hook file_alloc_security. That is, the return value rule is bypassed. This patch adds restriction for tail call to prevent such bypasses. Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Link: https://lore.kernel.org/r/20240719110059.797546-4-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> [Minor conflict resolved due to code context change.] Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com> Signed-off-by: He Zhe <zhe.he@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25bpf: avoid holding freeze_mutex during mmap operationAndrii Nakryiko1-7/+10
commit bc27c52eea189e8f7492d40739b7746d67b65beb upstream. We use map->freeze_mutex to prevent races between map_freeze() and memory mapping BPF map contents with writable permissions. The way we naively do this means we'll hold freeze_mutex for entire duration of all the mm and VMA manipulations, which is completely unnecessary. This can potentially also lead to deadlocks, as reported by syzbot in [0]. So, instead, hold freeze_mutex only during writeability checks, bump (proactively) "write active" count for the map, unlock the mutex and proceed with mmap logic. And only if something went wrong during mmap logic, then undo that "write active" counter increment. [0] https://lore.kernel.org/bpf/678dcbc9.050a0220.303755.0066.GAE@google.com/ Fixes: fc9702273e2e ("bpf: Add mmap() support for BPF_MAP_TYPE_ARRAY") Reported-by: syzbot+4dc041c686b7c816a71e@syzkaller.appspotmail.com Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20250129012246.1515826-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David Sauerwein <dssauerw@amazon.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-07bpf: skip non exist keys in generic_map_lookup_batchYan Zhai1-13/+5
[ Upstream commit 5644c6b50ffee0a56c1e01430a8c88e34decb120 ] The generic_map_lookup_batch currently returns EINTR if it fails with ENOENT and retries several times on bpf_map_copy_value. The next batch would start from the same location, presuming it's a transient issue. This is incorrect if a map can actually have "holes", i.e. "get_next_key" can return a key that does not point to a valid value. At least the array of maps type may contain such holes legitly. Right now these holes show up, generic batch lookup cannot proceed any more. It will always fail with EINTR errors. Rather, do not retry in generic_map_lookup_batch. If it finds a non existing element, skip to the next key. This simple solution comes with a price that transient errors may not be recovered, and the iteration might cycle back to the first key under parallel deletion. For example, Hou Tao <houtao@huaweicloud.com> pointed out a following scenario: For LPM trie map: (1) ->map_get_next_key(map, prev_key, key) returns a valid key (2) bpf_map_copy_value() return -ENOMENT It means the key must be deleted concurrently. (3) goto next_key It swaps the prev_key and key (4) ->map_get_next_key(map, prev_key, key) again prev_key points to a non-existing key, for LPM trie it will treat just like prev_key=NULL case, the returned key will be duplicated. With the retry logic, the iteration can continue to the key next to the deleted one. But if we directly skip to the next key, the iteration loop would restart from the first key for the lpm_trie type. However, not all races may be recovered. For example, if current key is deleted after instead of before bpf_map_copy_value, or if the prev_key also gets deleted, then the loop will still restart from the first key for lpm_tire anyway. For generic lookup it might be better to stay simple, i.e. just skip to the next key. To guarantee that the output keys are not duplicated, it is better to implement map type specific batch operations, which can properly lock the trie and synchronize with concurrent mutators. Fixes: cb4d03ab499d ("bpf: Add generic support for lookup batch op") Closes: https://lore.kernel.org/bpf/Z6JXtA1M5jAZx8xD@debian.debian/ Signed-off-by: Yan Zhai <yan@cloudflare.com> Acked-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/85618439eea75930630685c467ccefeac0942e2b.1739171594.git.yan@cloudflare.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-17bpf: Fix overloading of MEM_UNINIT's meaningDaniel Borkmann1-40/+36
commit 8ea607330a39184f51737c6ae706db7fdca7628e upstream. Lonial reported an issue in the BPF verifier where check_mem_size_reg() has the following code: if (!tnum_is_const(reg->var_off)) /* For unprivileged variable accesses, disable raw * mode so that the program is required to * initialize all the memory that the helper could * just partially fill up. */ meta = NULL; This means that writes are not checked when the register containing the size of the passed buffer has not a fixed size. Through this bug, a BPF program can write to a map which is marked as read-only, for example, .rodata global maps. The problem is that MEM_UNINIT's initial meaning that "the passed buffer to the BPF helper does not need to be initialized" which was added back in commit 435faee1aae9 ("bpf, verifier: add ARG_PTR_TO_RAW_STACK type") got overloaded over time with "the passed buffer is being written to". The problem however is that checks such as the above which were added later via 06c1c049721a ("bpf: allow helpers access to variable memory") set meta to NULL in order force the user to always initialize the passed buffer to the helper. Due to the current double meaning of MEM_UNINIT, this bypasses verifier write checks to the memory (not boundary checks though) and only assumes the latter memory is read instead. Fix this by reverting MEM_UNINIT back to its original meaning, and having MEM_WRITE as an annotation to BPF helpers in order to then trigger the BPF verifier checks for writing to memory. Some notes: check_arg_pair_ok() ensures that for ARG_CONST_SIZE{,_OR_ZERO} we can access fn->arg_type[arg - 1] since it must contain a preceding ARG_PTR_TO_MEM. For check_mem_reg() the meta argument can be removed altogether since we do check both BPF_READ and BPF_WRITE. Same for the equivalent check_kfunc_mem_size_reg(). Fixes: 7b3552d3f9f6 ("bpf: Reject writes for PTR_TO_MAP_KEY in check_helper_mem_access") Fixes: 97e6d7dab1ca ("bpf: Check PTR_TO_MEM | MEM_RDONLY in check_helper_mem_access") Fixes: 15baa55ff5b0 ("bpf/verifier: allow all functions to read user provided context") Reported-by: Lonial Con <kongln9170@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241021152809.33343-2-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: BRUNO VERNAY <bruno.vernay@se.com> Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17bpf: Add MEM_WRITE attributeDaniel Borkmann3-7/+7
commit 6fad274f06f038c29660aa53fbad14241c9fd976 upstream. Add a MEM_WRITE attribute for BPF helper functions which can be used in bpf_func_proto to annotate an argument type in order to let the verifier know that the helper writes into the memory passed as an argument. In the past MEM_UNINIT has been (ab)used for this function, but the latter merely tells the verifier that the passed memory can be uninitialized. There have been bugs with overloading the latter but aside from that there are also cases where the passed memory is read + written which currently cannot be expressed, see also 4b3786a6c539 ("bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error"). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241021152809.33343-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: BRUNO VERNAY <bruno.vernay@se.com> Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com> Stable-dep-of: 8ea607330a39 ("bpf: Fix overloading of MEM_UNINIT's meaning") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-09bpf: fix potential error returnAnton Protopopov1-1/+5
[ Upstream commit c4441ca86afe4814039ee1b32c39d833c1a16bbc ] The bpf_remove_insns() function returns WARN_ON_ONCE(error), where error is a result of bpf_adj_branches(), and thus should be always 0 However, if for any reason it is not 0, then it will be converted to boolean by WARN_ON_ONCE and returned to user space as 1, not an actual error value. Fix this by returning the original err after the WARN check. Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241210114245.836164-1-aspsk@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-02bpf: Check validity of link->type in bpf_link_show_fdinfo()Hou Tao1-4/+9
commit 8421d4c8762bd022cb491f2f0f7019ef51b4f0a7 upstream. If a newly-added link type doesn't invoke BPF_LINK_TYPE(), accessing bpf_link_type_strs[link->type] may result in an out-of-bounds access. To spot such missed invocations early in the future, checking the validity of link->type in bpf_link_show_fdinfo() and emitting a warning when such invocations are missed. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241024013558.1135167-3-houtao@huaweicloud.com [ shung-hsi.yu: break up existing seq_printf() call since commit 68b04864ca42 ("bpf: Create links for BPF struct_ops maps.") is not present ] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-19bpf: sync_linked_regs() must preserve subreg_defEduard Zingerman1-1/+4
commit e9bd9c498cb0f5843996dbe5cbce7a1836a83c70 upstream. Range propagation must not affect subreg_def marks, otherwise the following example is rewritten by verifier incorrectly when BPF_F_TEST_RND_HI32 flag is set: 0: call bpf_ktime_get_ns call bpf_ktime_get_ns 1: r0 &= 0x7fffffff after verifier r0 &= 0x7fffffff 2: w1 = w0 rewrites w1 = w0 3: if w0 < 10 goto +0 --------------> r11 = 0x2f5674a6 (r) 4: r1 >>= 32 r11 <<= 32 (r) 5: r0 = r1 r1 |= r11 (r) 6: exit; if w0 < 0xa goto pc+0 r1 >>= 32 r0 = r1 exit (or zero extension of w1 at (2) is missing for architectures that require zero extension for upper register half). The following happens w/o this patch: - r0 is marked as not a subreg at (0); - w1 is marked as subreg at (2); - w1 subreg_def is overridden at (3) by copy_register_state(); - w1 is read at (5) but mark_insn_zext() does not mark (2) for zero extension, because w1 subreg_def is not set; - because of BPF_F_TEST_RND_HI32 flag verifier inserts random value for hi32 bits of (2) (marked (r)); - this random value is read at (5). Fixes: 75748837b7e5 ("bpf: Propagate scalar ranges through register assignments.") Reported-by: Lonial Con <kongln9170@gmail.com> Signed-off-by: Lonial Con <kongln9170@gmail.com> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Closes: https://lore.kernel.org/bpf/7e2aa30a62d740db182c170fdd8f81c596df280d.camel@gmail.com Link: https://lore.kernel.org/bpf/20240924210844.1758441-1-eddyz87@gmail.com [ shung-hsi.yu: sync_linked_regs() was called find_equal_scalars() before commit 4bf79f9be434 ("bpf: Track equal scalars history on per-instruction level"), and modification is done because there is only a single call to copy_register_state() before commit 98d7ca374ba4 ("bpf: Track delta between "linked" registers."). ] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14bpf: Fix helper writes to read-only mapsDaniel Borkmann3-39/+11
commit 32556ce93bc45c730829083cb60f95a2728ea48b upstream. Lonial found an issue that despite user- and BPF-side frozen BPF map (like in case of .rodata), it was still possible to write into it from a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT} as arguments. In check_func_arg() when the argument is as mentioned, the meta->raw_mode is never set. Later, check_helper_mem_access(), under the case of PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the subsequent call to check_map_access_type() and given the BPF map is read-only it succeeds. The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT when results are written into them as opposed to read out of them. The latter indicates that it's okay to pass a pointer to uninitialized memory as the memory is written to anyway. However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM just with additional alignment requirement. So it is better to just get rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the fixed size memory types. For this, add MEM_ALIGNED to additionally ensure alignment given these helpers write directly into the args via *<ptr> = val. The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>). MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated argument types, since in !MEM_FIXED_SIZE cases the verifier does not know the buffer si