{"id":"CVE-2026-74729","state":"PUBLISHED","title":"soc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsoc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read\n\nput_fifo_with_discard() acts as both producer and consumer on the kfifo:\nit calls kfifo_skip() (advances out) and kfifo_put() (advances in) from\nthe IRQ handler without synchronizing with snoop_file_read(), which also\nconsumes via kfifo_to_user(). On SMP systems this concurrent access can\nleave (in - out) larger than the ring buffer, so __kfifo_to_user()'s clamp\nto (in - out) is ineffective and kfifo_copy_to_user() can attempt a\ncopy_to_user() past the kmalloc-2k backing store:\n\n  usercopy: Kernel memory exposure attempt detected from SLUB object\n  'kmalloc-2k' (offset 0, size 2049)!\n  kernel BUG at mm/usercopy.c!\n  Call trace:\n   usercopy_abort\n   __check_heap_object\n   __check_object_size\n   kfifo_copy_to_user\n   __kfifo_to_user\n   snoop_file_read\n   vfs_read\n\nSerialize kfifo access with a per-channel spinlock shared between the\nIRQ handler (producer) and the file reader (consumer).  Annotate @fifo\nwith __guarded_by(&lock) and opt the driver into context analysis so the\ncompiler enforces that all fifo access holds the lock.","publishedAt":"2026-08-22T15:33:19.037Z","updatedAt":"2026-10-30T12:30:24.911Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"f62afe827c52c300c64715631e6ac9e576c5112d","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"b87c0d24386ed5106feac12034fe09d893ccb469","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"afe2527eae0b51d5e8ddd77293afab3a5a1311a4","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"868c478abce858135db3eb65548a577e4b6747ac","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"131ab677b03349a5ae48da8722ec7075b37ec66e","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/soc/aspeed/Makefile","drivers/soc/aspeed/aspeed-lpc-snoop.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.19","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/soc/aspeed/Makefile","drivers/soc/aspeed/aspeed-lpc-snoop.c"]}],"references":["https://git.kernel.org/stable/c/f62afe827c52c300c64715631e6ac9e576c5112d","https://git.kernel.org/stable/c/b87c0d24386ed5106feac12034fe09d893ccb469","https://git.kernel.org/stable/c/afe2527eae0b51d5e8ddd77293afab3a5a1311a4","https://git.kernel.org/stable/c/868c478abce858135db3eb65548a577e4b6747ac","https://git.kernel.org/stable/c/131ab677b03349a5ae48da8722ec7075b37ec66e","https://git.kernel.org/stable/c/1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f"],"weaknesses":[],"ingestedAt":"2026-10-30T12:48:04.825Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74729.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74729","state":"PUBLISHED","datePublished":"2026-08-22T15:33:19.037Z","dateUpdated":"2026-10-30T12:30:24.911Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.929Z"},"containers":{"cna":{"title":"soc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsoc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read\n\nput_fifo_with_discard() acts as both producer and consumer on the kfifo:\nit calls kfifo_skip() (advances out) and kfifo_put() (advances in) from\nthe IRQ handler without synchronizing with snoop_file_read(), which also\nconsumes via kfifo_to_user(). On SMP systems this concurrent access can\nleave (in - out) larger than the ring buffer, so __kfifo_to_user()'s clamp\nto (in - out) is ineffective and kfifo_copy_to_user() can attempt a\ncopy_to_user() past the kmalloc-2k backing store:\n\n  usercopy: Kernel memory exposure attempt detected from SLUB object\n  'kmalloc-2k' (offset 0, size 2049)!\n  kernel BUG at mm/usercopy.c!\n  Call trace:\n   usercopy_abort\n   __check_heap_object\n   __check_object_size\n   kfifo_copy_to_user\n   __kfifo_to_user\n   snoop_file_read\n   vfs_read\n\nSerialize kfifo access with a per-channel spinlock shared between the\nIRQ handler (producer) and the file reader (consumer).  Annotate @fifo\nwith __guarded_by(&lock) and opt the driver into context analysis so the\ncompiler enforces that all fifo access holds the lock."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"f62afe827c52c300c64715631e6ac9e576c5112d","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"b87c0d24386ed5106feac12034fe09d893ccb469","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"afe2527eae0b51d5e8ddd77293afab3a5a1311a4","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"868c478abce858135db3eb65548a577e4b6747ac","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"131ab677b03349a5ae48da8722ec7075b37ec66e","versionType":"git"},{"version":"3772e5da445420543b25825ac2b5971f3743f6e8","status":"affected","lessThan":"1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/soc/aspeed/Makefile","drivers/soc/aspeed/aspeed-lpc-snoop.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.19","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/soc/aspeed/Makefile","drivers/soc/aspeed/aspeed-lpc-snoop.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f62afe827c52c300c64715631e6ac9e576c5112d"},{"url":"https://git.kernel.org/stable/c/b87c0d24386ed5106feac12034fe09d893ccb469"},{"url":"https://git.kernel.org/stable/c/afe2527eae0b51d5e8ddd77293afab3a5a1311a4"},{"url":"https://git.kernel.org/stable/c/868c478abce858135db3eb65548a577e4b6747ac"},{"url":"https://git.kernel.org/stable/c/131ab677b03349a5ae48da8722ec7075b37ec66e"},{"url":"https://git.kernel.org/stable/c/1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:30:24.911Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}