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9 daysstring: add mem_is_zero() helper to check if memory area is all zerosJani Nikula1-0/+12
[ Upstream commit 3942bb49728ad9e1f94d953a88af169a8f5d8099 ] Almost two thirds of the memchr_inv() usages check if the memory area is all zeros, with no interest in where in the buffer the first non-zero byte is located. Checking for !memchr_inv(s, 0, n) is also not very intuitive or discoverable. Add an explicit mem_is_zero() helper for this use case. Reviewed-by: Kees Cook <kees@kernel.org> Reviewed-by: Andy Shevchenko <andy@kernel.org> Link: https://patchwork.freedesktop.org/patch/msgid/20240814100035.3100852-1-jani.nikula@intel.com Signed-off-by: Jani Nikula <jani.nikula@intel.com> Stable-dep-of: 3e6ccd790ed6 ("gpio: cdev: check if uAPI v2 config attributes are correctly zeroed") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysbtrfs: tracepoints: fix sleep while in atomic context in btrfs_sync_file()Filipe Manana1-3/+1
[ Upstream commit c73370c677646e86fc4b1780fb07027bdf847375 ] The trace event btrfs_sync_file() is called in an atomic context (all trace events are) and its call to dput(), which is needed due to the call to dget_parent(), can sleep, triggering a kernel splat. This can be reproduced by enabling the trace event and running btrfs/056 from fstests for example. The splat shown in dmesg is the following: [53.919] BUG: sleeping function called from invalid context at fs/dcache.c:970 [53.947] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 32773, name: xfs_io [53.988] preempt_count: 2, expected: 0 [53.967] RCU nest depth: 0, expected: 0 [53.943] Preemption disabled at: [53.944] [<0000000000000000>] 0x0 [54.078] CPU: 0 UID: 0 PID: 32773 Comm: xfs_io Tainted: G W 7.1.0-rc1-btrfs-next-232+ #1 PREEMPT(full) [54.070] Tainted: [W]=WARN [54.071] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014 [54.072] Call Trace: [54.074] <TASK> [54.076] dump_stack_lvl+0x56/0x80 [54.079] __might_resched.cold+0xd6/0x10f [54.072] dput.part.0+0x24/0x110 [54.078] trace_event_raw_event_btrfs_sync_file+0x75/0x140 [btrfs] [54.089] btrfs_sync_file+0x1ed/0x530 [btrfs] [54.087] ? __handle_mm_fault+0x8ae/0xed0 [54.089] btrfs_do_write_iter+0x172/0x210 [btrfs] [54.091] vfs_write+0x21f/0x450 [54.094] __x64_sys_pwrite64+0x8d/0xc0 [54.096] ? do_user_addr_fault+0x20c/0x670 [54.099] do_syscall_64+0x60/0xf20 [54.092] ? clear_bhb_loop+0x60/0xb0 [54.094] entry_SYSCALL_64_after_hwframe+0x76/0x7e So stop using dget_parent() and dput() and access the parent dentry directly as dentry->d_parent. This is also what ext4 is doing in its equivalent trace event ext4_sync_file_enter(). Fixes: a85b46db143f ("btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file()") Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysipv6: rename and move ip6_dst_lookup_tunnel()Beniamino Galvani2-6/+7
[ Upstream commit fc47e86dbfb75a864c0c9dd8e78affb6506296bb ] At the moment ip6_dst_lookup_tunnel() is used only by bareudp. Ideally, other UDP tunnel implementations should use it, but to do so the function needs to accept new parameters that are specific for UDP tunnels, such as the ports. Prepare for these changes by renaming the function to udp_tunnel6_dst_lookup() and move it to file net/ipv6/ip6_udp_tunnel.c. This is similar to what already done for IPv4 in commit bf3fcbf7e7a0 ("ipv4: rename and move ip_route_output_tunnel()"). Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: aa6c6d9ee064 ("bareudp: fix NULL pointer dereference in bareudp_fill_metadata_dst()") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysipv4: add new arguments to udp_tunnel_dst_lookup()Beniamino Galvani1-3/+5
[ Upstream commit 72fc68c6356b663a8763f02d9b0ec773d59a4949 ] We want to make the function more generic so that it can be used by other UDP tunnel implementations such as geneve and vxlan. To do that, add the following arguments: - source and destination UDP port; - ifindex of the output interface, needed by vxlan; - the tos, because in some cases it is not taken from struct ip_tunnel_info (for example, when it's inherited from the inner packet); - the dst cache, because not all tunnel types (e.g. vxlan) want to use the one from struct ip_tunnel_info. With these parameters, the function no longer needs the full struct ip_tunnel_info as argument and we can pass only the relevant part of it (struct ip_tunnel_key). Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: aa6c6d9ee064 ("bareudp: fix NULL pointer dereference in bareudp_fill_metadata_dst()") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysipv4: remove "proto" argument from udp_tunnel_dst_lookup()Beniamino Galvani1-1/+1
[ Upstream commit 78f3655adcb52412275f282267ee771421731632 ] The function is now UDP-specific, the protocol is always IPPROTO_UDP. Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: aa6c6d9ee064 ("bareudp: fix NULL pointer dereference in bareudp_fill_metadata_dst()") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysipv4: rename and move ip_route_output_tunnel()Beniamino Galvani2-6/+6
[ Upstream commit bf3fcbf7e7a08015d3b169bad6281b29d45c272d ] At the moment ip_route_output_tunnel() is used only by bareudp. Ideally, other UDP tunnel implementations should use it, but to do so the function needs to accept new parameters that are specific for UDP tunnels, such as the ports. Prepare for these changes by renaming the function to udp_tunnel_dst_lookup() and move it to file net/ipv4/udp_tunnel_core.c. Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: aa6c6d9ee064 ("bareudp: fix NULL pointer dereference in bareudp_fill_metadata_dst()") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 dayscdrom, scsi: sr: propagate read-only status to block layer via set_disk_ro()Daan De Meyer1-0/+1
[ Upstream commit 0898a817621a2f0cddca8122d9b974003fe5036d ] The cdrom core never calls set_disk_ro() for a registered device, so BLKROGET on a CD-ROM device always returns 0 (writable), even when the drive has no write capabilities and writes will inevitably fail. This causes problems for userspace that relies on BLKROGET to determine whether a block device is read-only. For example, systemd's loop device setup uses BLKROGET to decide whether to create a loop device with LO_FLAGS_READ_ONLY. Without the read-only flag, writes pass through the loop device to the CD-ROM and fail with I/O errors. systemd-fsck similarly checks BLKROGET to decide whether to run fsck in no-repair mode (-n). The write-capability bits in cdi->mask come from two different sources: CDC_DVD_RAM and CDC_CD_RW are populated by the driver from the MODE SENSE capabilities page (page 0x2A) before register_cdrom() is called, while CDC_MRW_W and CDC_RAM require the MMC GET CONFIGURATION command and were only probed by cdrom_open_write() at device open time. This meant that any attempt to compute the writable state from the full mask at probe time was incorrect, because the GET CONFIGURATION bits were still unset (and cdi->mask is initialized such that capabilities are assumed present). Fix this by factoring the GET CONFIGURATION probing out of cdrom_open_write() into a new exported helper, cdrom_probe_write_features(), and having sr call it from sr_probe() right after get_capabilities() has populated the MODE SENSE bits. register_cdrom() then calls set_disk_ro() based on the full write-capability mask (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW) so the block layer reflects the drive's actual write support. The feature queries used (CDF_MRW and CDF_RWRT via GET CONFIGURATION with RT=00) report drive-level capabilities that are persistent across media, so a single probe before register_cdrom() is sufficient and the redundant probe at open time is dropped. With set_disk_ro() now accurate, the long-vestigial cd->writeable flag in sr can go: get_capabilities() used to set cd->writeable based on the same four mask bits, but because CDC_MRW_W and CDC_RAM default to "capability present" in cdi->mask and aren't touched by MODE SENSE, the condition that gated cd->writeable was always true, making it unconditionally 1. Replace the corresponding gate in sr_init_command() with get_disk_ro(cd->disk), which turns a previously no-op check into a real one and also catches kernel-internal bio writers that bypass blkdev_write_iter()'s bdev_read_only() check. The sd driver (SCSI disks) does not have this problem because it checks the MODE SENSE Write Protect bit and calls set_disk_ro() accordingly. The sr driver cannot use the same approach because the MMC specification does not define the WP bit in the MODE SENSE device-specific parameter byte for CD-ROM devices. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Daan De Meyer <daan@amutable.com> Reviewed-by: Phillip Potter <phil@philpotter.co.uk> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Phillip Potter <phil@philpotter.co.uk> Link: https://patch.msgid.link/20260427210139.1400-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysrtc: introduce features bitfieldAlexandre Belloni2-0/+7
[ Upstream commit 7ae41220ef5831674f446baef19bfe1b31358260 ] Introduce a bitfield to allow the drivers to announce the available features for an RTC. The main use case would be to better handle alarms, that could be present or not or have a minute resolution or may need a correct week day to be set. Use the newly introduced RTC_FEATURE_ALARM bit to then test whether alarms are available instead of relying on the presence of ops->set_alarm. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210110231752.1418816-2-alexandre.belloni@bootlin.com Stable-dep-of: 0fedce7244e4 ("rtc: abx80x: Disable alarm feature if no interrupt attached") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysnet: sched: gred/red: remove unused variables in struct red_statsZhengchao Shao1-1/+0
[ Upstream commit 4516c873e3b55856012ddd6db9d4366ce3c60c5d ] The variable "other" in the struct red_stats is not used. Remove it. Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: a8f5192809ca ("net/sched: sch_red: annotate data-races in red_dump_stats()") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysnet/sched: sch_pie: annotate data-races in pie_dump_stats()Eric Dumazet1-1/+1
[ Upstream commit 5154561d9b119f781249f8e845fecf059b38b483 ] pie_dump_stats() only runs with RTNL held, reading fields that can be changed in qdisc fast path. Add READ_ONCE()/WRITE_ONCE() annotations. Alternative would be to acquire the qdisc spinlock, but our long-term goal is to make qdisc dump operations lockless as much as we can. tc_pie_xstats fields don't need to be latched atomically, otherwise this bug would have been caught earlier. Fixes: edb09eb17ed8 ("net: sched: do not acquire qdisc spinlock in qdisc/class stats dump") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/20260421142944.4009941-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 dayspppoe: drop PFC framesQingfang Deng1-0/+16
[ Upstream commit cc1ff87bce1ccd38410ab10960f576dcd17db679 ] RFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT RECOMMENDED for PPPoE. In practice, pppd does not support negotiating PFC for PPPoE sessions, and the current PPPoE driver assumes an uncompressed (2-byte) protocol field. However, the generic PPP layer function ppp_input() is not aware of the negotiation result, and still accepts PFC frames. If a peer with a broken implementation or an attacker sends a frame with a compressed (1-byte) protocol field, the subsequent PPP payload is shifted by one byte. This causes the network header to be 4-byte misaligned, which may trigger unaligned access exceptions on some architectures. To reduce the attack surface, drop PPPoE PFC frames. Introduce ppp_skb_is_compressed_proto() helper function to be used in both ppp_generic.c and pppoe.c to avoid open-coding. Fixes: 7fb1b8ca8fa1 ("ppp: Move PFC decompression to PPP generic layer") Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260415022456.141758-2-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysflow_dissector: Add PPPoE dissectorsWojciech Drewek2-0/+27
[ Upstream commit 46126db9c86110e5fc1e369b9bb89735ddefdae4 ] Allow to dissect PPPoE specific fields which are: - session ID (16 bits) - ppp protocol (16 bits) - type (16 bits) - this is PPPoE ethertype, for now only ETH_P_PPP_SES is supported, possible ETH_P_PPP_DISC in the future The goal is to make the following TC command possible: # tc filter add dev ens6f0 ingress prio 1 protocol ppp_ses \ flower \ pppoe_sid 12 \ ppp_proto ip \ action drop Note that only PPPoE Session is supported. Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com> Acked-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Stable-dep-of: cc1ff87bce1c ("pppoe: drop PFC frames") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysflow_dissector: Add number of vlan tags dissectorBoris Sukholitko1-0/+9
[ Upstream commit 34951fcf26c59e78ae430fba1fce7c08b1871249 ] Our customers in the fiber telecom world have network configurations where they would like to control their traffic according to the number of tags appearing in the packet. For example, TR247 GPON conformance test suite specification mostly talks about untagged, single, double tagged packets and gives lax guidelines on the vlan protocol vs. number of vlan tags. This is different from the common IT networks where 802.1Q and 802.1ad protocols are usually describe single and double tagged packet. GPON configurations that we work with have arbitrary mix the above protocols and number of vlan tags in the packet. The goal is to make the following TC commands possible: tc filter add dev eth1 ingress flower \ num_of_vlans 1 vlan_prio 5 action drop From our logs, we have redirect rules such that: tc filter add dev $GPON ingress flower num_of_vlans $N \ action mirred egress redirect dev $DEV where N can range from 0 to 3 and $DEV is the function of $N. Also there are rules setting skb mark based on the number of vlans: tc filter add dev $GPON ingress flower num_of_vlans $N vlan_prio \ $P action skbedit mark $M This new dissector allows extracting the number of vlan tags existing in the packet. Signed-off-by: Boris Sukholitko <boris.sukholitko@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: cc1ff87bce1c ("pppoe: drop PFC frames") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 dayslib/hexdump: print_hex_dump_bytes() calls print_hex_dump_debug()Geert Uytterhoeven1-2/+3
[ Upstream commit 36776b7f8a8955b4e75b5d490a75fee0c7a2a7ef ] print_hex_dump_bytes() claims to be a simple wrapper around print_hex_dump(), but it actally calls print_hex_dump_debug(), which means no output is printed if (dynamic) DEBUG is disabled. Update the documentation to match the implementation. Fixes: 091cb0994edd20d6 ("lib/hexdump: make print_hex_dump_bytes() a nop on !DEBUG builds") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://patch.msgid.link/3d5c3069fd9102ecaf81d044b750cd613eb72a08.1774970392.git.geert+renesas@glider.be Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysdt-bindings: clock: qcom,dispcc-sc7180: Define MDSS resetsKonrad Dybcio1-1/+6
[ Upstream commit fc6e29d42872680dca017f2e5169eefe971f8d89 ] The MDSS resets have so far been left undescribed. Fix that. Fixes: 75616da71291 ("dt-bindings: clock: Introduce QCOM sc7180 display clock bindings") Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com> Reviewed-by: Taniya Das <taniya.das@oss.qualcomm.com> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com> Tested-by: Val Packett <val@packett.cool> # sc7180-ecs-liva-qc710 Link: https://lore.kernel.org/r/20260120-topic-7180_dispcc_bcr-v1-1-0b1b442156c3@oss.qualcomm.com Signed-off-by: Bjorn Andersson <andersson@kernel.org> Stable-dep-of: b0bc6011c549 ("clk: qcom: dispcc-sc7180: Add missing MDSS resets") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysdev_printk: add new dev_err_probe() helpersNuno Sa1-0/+8
[ Upstream commit dbbe7eaf0e4795bf003ac06872aaf52b6b6b1310 ] This is similar to dev_err_probe() but for cases where an ERR_PTR() or ERR_CAST() is to be returned simplifying patterns like: dev_err_probe(dev, ret, ...); return ERR_PTR(ret) or dev_err_probe(dev, PTR_ERR(ptr), ...); return ERR_CAST(ptr) Signed-off-by: Nuno Sa <nuno.sa@analog.com> Link: https://patch.msgid.link/20240606-dev-add_dev_errp_probe-v3-1-51bb229edd79@analog.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Stable-dep-of: 797cc011ae02 ("backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysdriver core: Move dev_err_probe() to where it belogsAndy Shevchenko2-2/+2
[ Upstream commit 9e0cace7a6254070159ebd86497eadc29ea307ca ] dev_err_probe() belongs to the printing API, hence move the definition from device.h to dev_printk.h. There is no change to the callers at all, since: 1) implementation is located in the same core.c; 2) dev_printk.h is guaranteed to be included by device.h. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Link: https://lore.kernel.org/r/20230721131309.16821-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 797cc011ae02 ("backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysdriver core: device.h: remove extern from function prototypesGreg Kroah-Hartman1-2/+1
[ Upstream commit f43243c66e5e9ad839d235f82a58e73a7e7612af ] The kernel coding style does not require 'extern' in function prototypes in .h files, so remove them from include/linux/device.h as they are not needed. Acked-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230324122711.2664537-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 797cc011ae02 ("backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysquota: Fix race of dquot_scan_active() with quota deactivationJan Kara1-8/+1
[ Upstream commit e93ab401da4b2e2c1b8ef2424de2f238d51c8b2d ] dquot_scan_active() can race with quota deactivation in quota_release_workfn() like: CPU0 (quota_release_workfn) CPU1 (dquot_scan_active) ============================== ============================== spin_lock(&dq_list_lock); list_replace_init( &releasing_dquots, &rls_head); /* dquot X on rls_head, dq_count == 0, DQ_ACTIVE_B still set */ spin_unlock(&dq_list_lock); synchronize_srcu(&dquot_srcu); spin_lock(&dq_list_lock); list_for_each_entry(dquot, &inuse_list, dq_inuse) { /* finds dquot X */ dquot_active(X) -> true atomic_inc(&X->dq_count); } spin_unlock(&dq_list_lock); spin_lock(&dq_list_lock); dquot = list_first_entry(&rls_head); WARN_ON_ONCE(atomic_read(&dquot->dq_count)); The problem is not only a cosmetic one as under memory pressure the caller of dquot_scan_active() can end up working on freed dquot. Fix the problem by making sure the dquot is removed from releasing list when we acquire a reference to it. Fixes: 869b6ea1609f ("quota: Fix slow quotaoff") Reported-by: Sam Sun <samsun1006219@gmail.com> Link: https://lore.kernel.org/all/CAEkJfYPTt3uP1vAYnQ5V2ZWn5O9PLhhGi5HbOcAzyP9vbXyjeg@mail.gmail.com Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysALSA: compress: Drop unused functionsTakashi Iwai1-2/+0
[ Upstream commit fc93c96fe34e10b873fef73e80cee52503f3a679 ] snd_compress_register() and snd_compress_deregister() API functions have been never used by in-tree drivers. Let's clean up the dead code. Acked-by: Vinod Koul <vkoul@kernel.org> Reviewed-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com> Link: https://lore.kernel.org/r/20210714162424.4412-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de> Stable-dep-of: 796e119e9b14 ("ALSA: core: Validate compress device numbers without dynamic minors") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysfirmware: dmi: Correct an indexing error in dmi.hMario Limonciello (AMD)1-0/+5
[ Upstream commit c064abc68e009d2cc18416e7132d9c25e03125b6 ] The entries later in enum dmi_entry_type don't match the SMBIOS specification¹. The entry for type 33: `64-Bit Memory Error Information` is not present and thus the index for all later entries is incorrect. Add it. Also, add missing entry types 43-46, while at it. ¹ Search for "System Management BIOS (SMBIOS) Reference Specification" [ bp: Drop the flaky SMBIOS spec URL. ] Fixes: 93c890dbe5287 ("firmware: Add DMI entry types to the headers") Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Jean Delvare <jdelvare@suse.de> Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com> Link: https://patch.msgid.link/20260307141024.819807-2-superm1@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
9 dayslocking: Fix rwlock support in <linux/spinlock_up.h>Bart Van Assche1-10/+10
[ Upstream commit 756a0e011cfca0b45a48464aa25b05d9a9c2fb0b ] Architecture support for rwlocks must be available whether or not CONFIG_DEBUG_SPINLOCK has been defined. Move the definitions of the arch_{read,write}_{lock,trylock,unlock}() macros such that these become visbile if CONFIG_DEBUG_SPINLOCK=n. This patch prepares for converting do_raw_{read,write}_trylock() into inline functions. Without this patch that conversion triggers a build failure for UP architectures, e.g. arm-ep93xx. I used the following kernel configuration to build the kernel for that architecture: CONFIG_ARCH_MULTIPLATFORM=y CONFIG_ARCH_MULTI_V7=n CONFIG_ATAGS=y CONFIG_MMU=y CONFIG_ARCH_MULTI_V4T=y CONFIG_CPU_LITTLE_ENDIAN=y CONFIG_ARCH_EP93XX=y Fixes: fb1c8f93d869 ("[PATCH] spinlock consolidation") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260313171510.230998-2-bvanassche@acm.org Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysfanotify: fix false positive on permission eventsMiklos Szeredi1-0/+1
commit 7746e3bd4cc19b5092e00d32d676e329bfcb6900 upstream. fsnotify_get_mark_safe() may return false for a mark on an unrelated group, which results in bypassing the permission check. Fix by skipping over detached marks that are not in the current group. CC: stable@vger.kernel.org Fixes: abc77577a669 ("fsnotify: Provide framework for dropping SRCU lock in ->handle_event") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Link: https://patch.msgid.link/20260410144950.156160-1-mszeredi@redhat.com Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 daysfbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-freeRajat Gupta1-0/+1
commit 8de779dc40d35d39fa07387b6f921eb11df0f511 upstream. dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages to userspace but sets no vm_ops on the VMA. This means the kernel cannot track active mmaps. When dlfb_realloc_framebuffer() replaces the backing buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated. On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages while userspace PTEs still reference them, resulting in a use-after-free: the process retains read/write access to freed kernel pages. Add vm_operations_struct with open/close callbacks that maintain an atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(), check mmap_count and return -EBUSY if the buffer is currently mapped, preventing buffer replacement while userspace holds stale PTEs. Tested with PoC using dummy_hcd + raw_gadget USB device emulation. Signed-off-by: Rajat Gupta <rajgupt@qti.qualcomm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 daysdriver core: Add kernel-doc for DEV_FLAG_COUNT enum valueDouglas Anderson1-0/+1
commit 5b484311507b5d403c1f7a45f6aa3778549e268b upstream. Even though nobody should use this value (except when declaring the "flags" bitmap), kernel-doc still gets upset that it's not documented. It reports: WARNING: ../include/linux/device.h:519 Enum value 'DEV_FLAG_COUNT' not described in enum 'struct_device_flags' Add the description of DEV_FLAG_COUNT. Fixes: a2225b6e834a ("driver core: Don't let a device probe until it's ready") Reported-by: Randy Dunlap <rdunlap@infradead.org> Closes: https://lore.kernel.org/f318cd43-81fd-48b9-abf7-92af85f12f91@infradead.org Signed-off-by: Douglas Anderson <dianders@chromium.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Link: https://patch.msgid.link/20260413195910.1.I23aca74fe2d3636a47df196a80920fecb2643220@changeid Signed-off-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 daystpm: avoid -Wunused-but-set-variableArnd Bergmann1-2/+7
commit 6f1d4d2ecfcd1b577dc87350ea965fe81f272e83 upstream. Outside of the EFI tpm code, the TPM_MEMREMAP()/TPM_MEMUNMAP functions are defined as trivial macros, leading to the mapping_size variable ending up unused: In file included from drivers/char/tpm/tpm-sysfs.c:16: In file included from drivers/char/tpm/tpm.h:28: include/linux/tpm_eventlog.h:167:6: error: variable 'mapping_size' set but not used [-Werror,-Wunused-but-set-variable] 167 | int mapping_size; Turn the stubs into inline functions to avoid this warning. Cc: stable@vger.kernel.org # v5.3+ Fixes: c46f3405692d ("tpm: Reserve the TPM final events table") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Thorsten Blum <thorsten.blum@linux.dev> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 daysdriver core: Don't let a device probe until it's readyDouglas Anderson1-0/+44
[ Upstream commit a2225b6e834a838ae3c93709760edc0a169eb2f2 ] The moment we link a "struct device" into the list of devices for the bus, it's possible probe can happen. This is because another thread can load the driver at any time and that can cause the device to probe. This has been seen in practice with a stack crawl that looks like this [1]: really_probe() __driver_probe_device() driver_probe_device() __driver_attach() bus_for_each_dev() driver_attach() bus_add_driver() driver_register() __platform_driver_register() init_module() [some module] do_one_initcall() do_init_module() load_module() __arm64_sys_finit_module() invoke_syscall() As a result of the above, it was seen that device_links_driver_bound() could be called for the device before "dev->fwnode->dev" was assigned. This prevented __fw_devlink_pickup_dangling_consumers() from being called which meant that other devices waiting on our driver's sub-nodes were stuck deferring forever. It's believed that this problem is showing up suddenly for two reasons: 1. Android has recently (last ~1 year) implemented an optimization to the order it loads modules [2]. When devices opt-in to this faster loading, modules are loaded one-after-the-other very quickly. This is unlike how other distributions do it. The reproduction of this problem has only been seen on devices that opt-in to Android's "parallel module loading". 2. Android devices typically opt-in to fw_devlink, and the most noticeable issue is the NULL "dev->fwnode->dev" in device_links_driver_bound(). fw_devlink is somewhat new code and also not in use by all Linux devices. Even though the specific symptom where "dev->fwnode->dev" wasn't assigned could be fixed by moving that assignment higher in device_add(), other parts of device_add() (like the call to device_pm_add()) are also important to run before probe. Only moving the "dev->fwnode->dev" assignment would likely fix the current symptoms but lead to difficult-to-debug problems in the future. Fix the problem by preventing probe until device_add() has run far enough that the device is ready to probe. If somehow we end up trying to probe before we're allowed, __driver_probe_device() will return -EPROBE_DEFER which will make certain the device is noticed. In the race condition that was seen with Android's faster module loading, we will temporarily add the device to the deferred list and then take it off immediately when device_add() probes the device. Instead of adding another flag to the bitfields already in "struct device", instead add a new "flags" field and use that. This allows us to freely change the bit from different thread without worrying about corrupting nearby bits (and means threads changing other bit won't corrupt us). [1] Captured on a machine running a downstream 6.6 kernel [2] https://cs.android.com/android/platform/superproject/main/+/main:system/core/libmodprobe/libmodprobe.cpp?q=LoadModulesParallel Cc: stable@vger.kernel.org Fixes: 2023c610dc54 ("Driver core: add new device to bus's list before probing") Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org> Reviewed-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://patch.msgid.link/20260406162231.v5.1.Id750b0fbcc94f23ed04b7aecabcead688d0d8c17@changeid Signed-off-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 dayspadata: Remove comment for reorder_workHerbert Xu1-1/+0
[ Upstream commit 82a0302e7167d0b7c6cde56613db3748f8dd806d ] Remove comment for reorder_work which no longer exists. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 71203f68c774 ("padata: Fix pd UAF once and for all") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Bin Lan <lanbincn@139.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 dayspadata: Fix pd UAF once and for allHerbert Xu1-3/+0
[ Upstream commit 71203f68c7749609d7fc8ae6ad054bdedeb24f91 ] There is a race condition/UAF in padata_reorder that goes back to the initial commit. A reference count is taken at the start of the process in padata_do_parallel, and released at the end in padata_serial_worker. This reference count is (and only is) required for padata_replace to function correctly. If padata_replace is never called then there is no issue. In the function padata_reorder which serves as the core of padata, as soon as padata is added to queue->serial.list, and the associated spin lock released, that padata may be processed and the reference count on pd would go away. Fix this by getting the next padata before the squeue->serial lock is released. In order to make this possible, simplify padata_reorder by only calling it once the next padata arrives. Fixes: 16295bec6398 ("padata: Generic parallelization/serialization interface") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> [ Adjust context of padata_find_next(). Replace cpumask_next_wrap(cpu, pd->cpumask.pcpu) with cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1, false) in padata_reorder() in v5.10 according to dc5bb9b769c9 ("cpumask: deprecate cpumask_next_wrap()") and f954a2d37637 ("padata: switch padata_find_next() to using cpumask_next_wrap()") . ] Signed-off-by: Bin Lan <lanbincn@139.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysusb: xhci: Make usb_host_endpoint.hcpriv survive endpoint_disable()Michal Pecio1-1/+2
commit 25e531b422dc2ac90cdae3b6e74b5cdeb081440d upstream. xHCI hardware maintains its endpoint state between add_endpoint() and drop_endpoint() calls followed by successful check_bandwidth(). So does the driver. Core may call endpoint_disable() during xHCI endpoint life, so don't clear host_ep->hcpriv then, because this breaks endpoint_reset(). If a driver calls usb_set_interface(), submits URBs which make host sequence state non-zero and calls usb_clear_halt(), the device clears its sequence state but xhci_endpoint_reset() bails out. The next URB malfunctions: USB2 loses one packet, USB3 gets Transaction Error or may not complete at all on some (buggy?) HCs from ASMedia and AMD. This is triggered by uvcvideo on bulk video devices. The code was copied from ehci_endpoint_disable() but it isn't needed here - hcpriv should only be NULL on emulated root hub endpoints. It might prevent resetting and inadvertently enabling a disabled and dropped endpoint, but core shouldn't try to reset dropped endpoints. Document xhci requirements regarding hcpriv. They are currently met. Fixes: 18b74067ac78 ("xhci: Fix use-after-free regression in xhci clear hub TT implementation") Cc: stable@vger.kernel.org Signed-off-by: Michal Pecio <michal.pecio@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://patch.msgid.link/20260402131342.2628648-26-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 daysrxrpc: Fix recvmsg() unconditional requeueDavid Howells1-0/+8
[ Upstream commit 2c28769a51deb6022d7fbd499987e237a01dd63a ] If rxrpc_recvmsg() fails because MSG_DONTWAIT was specified but the call at the front of the recvmsg queue already has its mutex locked, it requeues the call - whether or not the call is already queued. The call may be on the queue because MSG_PEEK was also passed and so the call was not dequeued or because the I/O thread requeued it. The unconditional requeue may then corrupt the recvmsg queue, leading to things like UAFs or refcount underruns. Fix this by only requeuing the call if it isn't already on the queue - and moving it to the front if it is already queued. If we don't queue it, we have to put the ref we obtained by dequeuing it. Also, MSG_PEEK doesn't dequeue the call so shouldn't call rxrpc_notify_socket() for the call if we didn't use up all the data on the queue, so fix that also. Fixes: 540b1c48c37a ("rxrpc: Fix deadlock between call creation and sendmsg/recvmsg") Reported-by: Faith <faith@zellic.io> Reported-by: Pumpkin Chang <pumpkin@devco.re> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Cc: stable@vger.kernel.org [Adapted to 5.10: use write_lock_bh/write_unlock_bh, trace_rxrpc_call directly for see-call tracing, 5.10 trace enum naming convention, and added entries to both plain enum and EM() macro list.] Signed-off-by: Jay Wang <wanjay@amazon.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysx86/uprobes: Fix XOL allocation failure for 32-bit tasksOleg Nesterov1-0/+1
[ Upstream commit d55c571e4333fac71826e8db3b9753fadfbead6a ] This script #!/usr/bin/bash echo 0 > /proc/sys/kernel/randomize_va_space echo 'void main(void) {}' > TEST.c # -fcf-protection to ensure that the 1st endbr32 insn can't be emulated gcc -m32 -fcf-protection=branch TEST.c -o test bpftrace -e 'uprobe:./test:main {}' -c ./test "hangs", the probed ./test task enters an endless loop. The problem is that with randomize_va_space == 0 get_unmapped_area(TASK_SIZE - PAGE_SIZE) called by xol_add_vma() can not just return the "addr == TASK_SIZE - PAGE_SIZE" hint, this addr is used by the stack vma. arch_get_unmapped_area_topdown() doesn't take TIF_ADDR32 into account and in_32bit_syscall() is false, this leads to info.high_limit > TASK_SIZE. vm_unmapped_area() happily returns the high address > TASK_SIZE and then get_unmapped_area() returns -ENOMEM after the "if (addr > TASK_SIZE - len)" check. handle_swbp() doesn't report this failure (probably it should) and silently restarts the probed insn. Endless loop. I think that the right fix should change the x86 get_unmapped_area() paths to rely on TIF_ADDR32 rather than in_32bit_syscall(). Note also that if CONFIG_X86_X32_ABI=y, in_x32_syscall() falsely returns true in this case because ->orig_ax = -1. But we need a simple fix for -stable, so this patch just sets TS_COMPAT if the probed task is 32-bit to make in_ia32_syscall() true. Fixes: 1b028f784e8c ("x86/mm: Introduce mmap_compat_base() for 32-bit mmap()") Reported-by: Paulo Andrade <pandrade@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/aV5uldEvV7pb4RA8@redhat.com/ Cc: stable@vger.kernel.org Link: https://patch.msgid.link/aWO7Fdxn39piQnxu@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 daysIB/mad: Don't call to function that might sleep while in atomic contextLeonid Ravich1-9/+4
commit 5c20311d76cbaeb7ed2ecf9c8b8322f8fc4a7ae3 upstream. Tracepoints are not allowed to sleep, as such the following splat is generated due to call to ib_query_pkey() in atomic context. WARNING: CPU: 0 PID: 1888000 at kernel/trace/ring_buffer.c:2492 rb_commit+0xc1/0x220 CPU: 0 PID: 1888000 Comm: kworker/u9:0 Kdump: loaded Tainted: G OE --------- - - 4.18.0-305.3.1.el8.x86_64 #1 Hardware name: Red Hat KVM, BIOS 1.13.0-2.module_el8.3.0+555+a55c8938 04/01/2014 Workqueue: ib-comp-unb-wq ib_cq_poll_work [ib_core] RIP: 0010:rb_commit+0xc1/0x220 RSP: 0000:ffffa8ac80f9bca0 EFLAGS: 00010202 RAX: ffff8951c7c01300 RBX: ffff8951c7c14a00 RCX: 0000000000000246 RDX: ffff8951c707c000 RSI: ffff8951c707c57c RDI: ffff8951c7c14a00 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8951c7c01300 R11: 0000000000000001 R12: 0000000000000246 R13: 0000000000000000 R14: ffffffff964c70c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8951fbc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f20e8f39010 CR3: 000000002ca10005 CR4: 0000000000170ef0 Call Trace: ring_buffer_unlock_commit+0x1d/0xa0 trace_buffer_unlock_commit_regs+0x3b/0x1b0 trace_event_buffer_commit+0x67/0x1d0 trace_event_raw_event_ib_mad_recv_done_handler+0x11c/0x160 [ib_core] ib_mad_recv_done+0x48b/0xc10 [ib_core] ? trace_event_raw_event_cq_poll+0x6f/0xb0 [ib_core] __ib_process_cq+0x91/0x1c0 [ib_core] ib_cq_poll_work+0x26/0x80 [ib_core] process_one_work+0x1a7/0x360 ? create_worker+0x1a0/0x1a0 worker_thread+0x30/0x390 ? create_worker+0x1a0/0x1a0 kthread+0x116/0x130 ? kthread_flush_work_fn+0x10/0x10 ret_from_fork+0x35/0x40 ---[ end trace 78ba8509d3830a16 ]--- Fixes: 821bf1de45a1 ("IB/MAD: Add recv path trace point") Signed-off-by: Leonid Ravich <lravich@gmail.com> Link: https://lore.kernel.org/r/Y2t5feomyznrVj7V@leonid-Inspiron-3421 Signed-off-by: Leon Romanovsky <leon@kernel.org> [ kovalev: bp to fix CVE-2022-50472 ] Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 dayswifi: mac80211: always free skb on ieee80211_tx_prepare_skb() failureFelix Fietkau1-0/+4
[ Upstream commit d5ad6ab61cbd89afdb60881f6274f74328af3ee9 ] ieee80211_tx_prepare_skb() has three error paths, but only two of them free the skb. The first error path (ieee80211_tx_prepare() returning TX_DROP) does not free it, while invoke_tx_handlers() failure and the fragmentation check both do. Add kfree_skb() to the first error path so all three are consistent, and remove the now-redundant frees in callers (ath9k, mt76, mac80211_hwsim) to avoid double-free. Document the skb ownership guarantee in the function's kdoc. Signed-off-by: Felix Fietkau <nbd@nbd.name> Link: https://patch.msgid.link/20260314065455.2462900-1-nbd@nbd.name Fixes: 06be6b149f7e ("mac80211: add ieee80211_tx_prepare_skb() helper function") Signed-off-by: Johannes Berg <johannes.berg@intel.com> [ Exclude changes to drivers/net/wireless/mediatek/mt76/scan.c as this file is first introduced by commit 31083e38548f("wifi: mt76: add code for emulating hardware scanning") after linux-6.14.] Signed-off-by: Li hongliang <1468888505@139.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysKVM: x86: Use scratch field in MMIO fragment to hold small write valuesSean Christopherson1-1/+2
commit 0b16e69d17d8c35c5c9d5918bf596c75a44655d3 upstream. When exiting to userspace to service an emulated MMIO write, copy the to-be-written value to a scratch field in the MMIO fragment if the size of the data payload is 8 bytes or less, i.e. can fit in a single chunk, instead of pointing the fragment directly at the source value. This fixes a class of use-after-free bugs that occur when the emulator initiates a write using an on-stack, local variable as the source, the write splits a page boundary, *and* both pages are MMIO pages. Because KVM's ABI only allows for physically contiguous MMIO requests, accesses that split MMIO pages are separated into two fragments, and are sent to userspace one at a time. When KVM attempts to complete userspace MMIO in response to KVM_RUN after the first fragment, KVM will detect the second fragment and generate a second userspace exit, and reference the on-stack variable. The issue is most visible if the second KVM_RUN is performed by a separate task, in which case the stack of the initiating task can show up as truly freed data. ================================================================== BUG: KASAN: use-after-free in complete_emulated_mmio+0x305/0x420 Read of size 1 at addr ffff888009c378d1 by task syz-executor417/984 CPU: 1 PID: 984 Comm: syz-executor417 Not tainted 5.10.0-182.0.0.95.h2627.eulerosv2r13.x86_64 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0xbe/0xfd print_address_description.constprop.0+0x19/0x170 __kasan_report.cold+0x6c/0x84 kasan_report+0x3a/0x50 check_memory_region+0xfd/0x1f0 memcpy+0x20/0x60 complete_emulated_mmio+0x305/0x420 kvm_arch_vcpu_ioctl_run+0x63f/0x6d0 kvm_vcpu_ioctl+0x413/0xb20 __se_sys_ioctl+0x111/0x160 do_syscall_64+0x30/0x40 entry_SYSCALL_64_after_hwframe+0x67/0xd1 RIP: 0033:0x42477d Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007faa8e6890e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004d7338 RCX: 000000000042477d RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00000000004d7330 R08: 00007fff28d546df R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004d733c R13: 0000000000000000 R14: 000000000040a200 R15: 00007fff28d54720 The buggy address belongs to the page: page:0000000029f6a428 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9c37 flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff) raw: 000fffffc0000000 0000000000000000 ffffea0000270dc8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888009c37780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888009c37800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888009c37880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888009c37900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888009c37980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== The bug can also be reproduced with a targeted KVM-Unit-Test by hacking KVM to fill a large on-stack variable in complete_emulated_mmio(), i.e. by overwrite the data value with garbage. Limit the use of the scratch fields to 8-byte or smaller accesses, and to just writes, as larger accesses and reads are not affect