bpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries
bpf_set_dentry_xattr and bpf_remove_dentry_xattr BPF kfuncs attempt to
lock the inode of the supplied dentry without checking if it is
NULL. If a negative dentry is passed (e.g. from
security_inode_create), d_inode(dentry) returns NULL, and
inode_lock(inode) will cause a NULL pointer dereference.
Trivially fix this by adding a NULL check for inode before attempting
to lock it, returning -EINVAL if it is NULL.
Additionally, drop WARN_ON(!inode) in bpf_xattr_read_permission() and
bpf_xattr_write_permission(). These warnings could be triggered by
passing a negative dentry to bpf_get_dentry_xattr() or the _locked
variants of the xattr kfuncs, potentially causing a Denial of Service
on systems with panic_on_warn enabled. Instead, simply return -EINVAL.
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Sat, 15 Aug 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-476 |
Sat, 15 Aug 2026 06:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: bpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries bpf_set_dentry_xattr and bpf_remove_dentry_xattr BPF kfuncs attempt to lock the inode of the supplied dentry without checking if it is NULL. If a negative dentry is passed (e.g. from security_inode_create), d_inode(dentry) returns NULL, and inode_lock(inode) will cause a NULL pointer dereference. Trivially fix this by adding a NULL check for inode before attempting to lock it, returning -EINVAL if it is NULL. Additionally, drop WARN_ON(!inode) in bpf_xattr_read_permission() and bpf_xattr_write_permission(). These warnings could be triggered by passing a negative dentry to bpf_get_dentry_xattr() or the _locked variants of the xattr kfuncs, potentially causing a Denial of Service on systems with panic_on_warn enabled. Instead, simply return -EINVAL. | |
| Title | bpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-15T05:59:11.450Z
Reserved: 2026-08-15T05:44:03.892Z
Link: CVE-2026-74400
No data.
Status : Received
Published: 2026-08-15T06:22:42.030
Modified: 2026-08-15T06:22:42.030
Link: CVE-2026-74400
No data.
OpenCVE Enrichment
Updated: 2026-08-15T14:00:08Z