GHSA-6HJ9-W6W6-X26P
Vulnerability from github – Published: 2026-08-22 18:30 – Updated: 2026-08-22 18:30In the Linux kernel, the following vulnerability has been resolved:
soc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read
put_fifo_with_discard() acts as both producer and consumer on the kfifo: it calls kfifo_skip() (advances out) and kfifo_put() (advances in) from the IRQ handler without synchronizing with snoop_file_read(), which also consumes via kfifo_to_user(). On SMP systems this concurrent access can leave (in - out) larger than the ring buffer, so __kfifo_to_user()'s clamp to (in - out) is ineffective and kfifo_copy_to_user() can attempt a copy_to_user() past the kmalloc-2k backing store:
usercopy: Kernel memory exposure attempt detected from SLUB object 'kmalloc-2k' (offset 0, size 2049)! kernel BUG at mm/usercopy.c! Call trace: usercopy_abort __check_heap_object __check_object_size kfifo_copy_to_user __kfifo_to_user snoop_file_read vfs_read
Serialize kfifo access with a per-channel spinlock shared between the IRQ handler (producer) and the file reader (consumer). Annotate @fifo with __guarded_by(&lock) and opt the driver into context analysis so the compiler enforces that all fifo access holds the lock.
{
"affected": [],
"aliases": [
"CVE-2026-74729"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-22T16:16:48Z",
"severity": null
},
"details": "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()\u0027s 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 \u0027kmalloc-2k\u0027 (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(\u0026lock) and opt the driver into context analysis so the\ncompiler enforces that all fifo access holds the lock.",
"id": "GHSA-6hj9-w6w6-x26p",
"modified": "2026-08-22T18:30:30Z",
"published": "2026-08-22T18:30:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74729"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/131ab677b03349a5ae48da8722ec7075b37ec66e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
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Nomenclature
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