CVE-2026-99173
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: eventfs: Free the eventfs_inode after an rcu grace period too tracefs_d_revalidate() reads ->is_freed of the eventfs_inode that dentry->d_fsdata points to, and ->d_revalidate() is called in rcu pathwalk mode with nothing but rcu_read_lock() held. The dentry itself stays around for such a walker, but tracefs_d_release() drops its reference to the eventfs_inode when the dentry is killed, and release_ei() then frees it after a grace period of eventfs_srcu. An SRCU grace period doesn't wait for rcu_read_lock() sections, so the walker can read an eventfs_inode that is already gone. With a pathwalk held up in tracefs_d_revalidate() while the dentry goes away: BUG: KASAN: slab-use-after-free in tracefs_d_revalidate+0x76/0x90 Read of size 1 at addr ff1100010152d8d0 by task walker/97 Call Trace: <TASK> tracefs_d_revalidate+0x76/0x90 lookup_fast+0x320/0x640 path_lookupat+0x160/0xb00 filename_lookup+0x1f1/0x5b0 vfs_statx+0xd7/0x3b0 vfs_fstatat+0x4d/0x90 __do_sys_newfstatat+0xa0/0x100 do_syscall_64+0x10e/0x5e0 entry_SYSCALL_64_after_hwframe+0x77/0x7f [...] Allocated by task 1: __kmalloc_cache_noprof+0x249/0x560 eventfs_create_dir+0x7a/0x590 event_create_dir+0x2fb/0xcf0 trace_add_event_call+0xbf/0x150 [...] Freed by task 11: kfree+0x1db/0x5b0 srcu_invoke_callbacks+0x3a3/0x620 process_one_work+0x937/0x1810 worker_thread+0x4f1/0xd60 Before commit 8e556432477e ("eventfs: Use SRCU for freeing eventfs_inodes") release_ei() used call_rcu(), which covered the walker, while eventfs_iterate() needs the SRCU grace period. Wait for both and chain call_rcu() from the SRCU callback.
View original CVE JSON
{
"id": "CVE-2026-99173",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-28T11:17:37.900",
"lastModified": "2026-10-28T11:17:37.900",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\neventfs: Free the eventfs_inode after an rcu grace period too\n\ntracefs_d_revalidate() reads ->is_freed of the eventfs_inode that\ndentry->d_fsdata points to, and ->d_revalidate() is called in rcu\npathwalk mode with nothing but rcu_read_lock() held. The dentry itself\nstays around for such a walker, but tracefs_d_release() drops its\nreference to the eventfs_inode when the dentry is killed, and\nrelease_ei() then frees it after a grace period of eventfs_srcu. An\nSRCU grace period doesn't wait for rcu_read_lock() sections, so the\nwalker can read an eventfs_inode that is already gone.\n\nWith a pathwalk held up in tracefs_d_revalidate() while the dentry goes\naway:\n\n BUG: KASAN: slab-use-after-free in tracefs_d_revalidate+0x76/0x90\n Read of size 1 at addr ff1100010152d8d0 by task walker/97\n Call Trace:\n <TASK>\n tracefs_d_revalidate+0x76/0x90\n lookup_fast+0x320/0x640\n path_lookupat+0x160/0xb00\n filename_lookup+0x1f1/0x5b0\n vfs_statx+0xd7/0x3b0\n vfs_fstatat+0x4d/0x90\n __do_sys_newfstatat+0xa0/0x100\n do_syscall_64+0x10e/0x5e0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n [...]\n Allocated by task 1:\n __kmalloc_cache_noprof+0x249/0x560\n eventfs_create_dir+0x7a/0x590\n event_create_dir+0x2fb/0xcf0\n trace_add_event_call+0xbf/0x150\n [...]\n Freed by task 11:\n kfree+0x1db/0x5b0\n srcu_invoke_callbacks+0x3a3/0x620\n process_one_work+0x937/0x1810\n worker_thread+0x4f1/0xd60\n\nBefore commit 8e556432477e (\"eventfs: Use SRCU for freeing\neventfs_inodes\") release_ei() used call_rcu(), which covered the walker,\nwhile eventfs_iterate() needs the SRCU grace period. Wait for both and\nchain call_rcu() from the SRCU callback."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/tracefs/event_inode.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "8e556432477e97ad6179c61b61a32bf5f1af2355",
"lessThan": "4586ef24ce390e8becb9f3e5852d5d3978b01c33",
"versionType": "git",
"status": "affected"
},
{
"version": "8e556432477e97ad6179c61b61a32bf5f1af2355",
"lessThan": "45fcfd5d9c10e0aa977ed5b9bd445707e01bb107",
"versionType": "git",
"status": "affected"
},
{
"version": "8e556432477e97ad6179c61b61a32bf5f1af2355",
"lessThan": "2cd88c498ecff8e22bf4c397b8eb226db70ac343",
"versionType": "git",
"status": "affected"
},
{
"version": "2ef3d120d19faba3dec35b10a025b00db0284373",
"versionType": "git",
"status": "affected"
},
{
"version": "384f383c5aa7bfd619d9f56a513a36e533428186",
"versionType": "git",
"status": "affected"
},
{
"version": "6.6.46",
"lessThan": "6.7",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.10.5",
"lessThan": "6.11",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/tracefs/event_inode.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.11",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.11",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.59",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.13",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/2cd88c498ecff8e22bf4c397b8eb226db70ac343",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4586ef24ce390e8becb9f3e5852d5d3978b01c33",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/45fcfd5d9c10e0aa977ed5b9bd445707e01bb107",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}