Description
In the Linux kernel, the following vulnerability has been resolved:
libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()
Since commit 1e7ab6f67824 ("anon_inode: rework assertions"),
path_noexec() warns when an anonymous-inode file is mmap'd from a
superblock that has not set SB_I_NOEXEC. dma-buf backs its files this
way and never set the flag, so mmap of any exported buffer trips the
warning on a CONFIG_DEBUG_VFS=y kernel:
WARNING: CPU: 11 PID: 121813 at fs/exec.c:118 path_noexec+0x47/0x50
do_mmap+0x2b5/0x680
vm_mmap_pgoff+0x129/0x210
ksys_mmap_pgoff+0x177/0x240
__x64_sys_mmap+0x33/0x70
init_pseudo() sets up internal SB_NOUSER mounts that are never
path-reachable. Set both flags here so every pseudo filesystem gets
them by default instead of each caller setting them.
SB_I_NODEV is inert for unreachable mounts. SB_I_NOEXEC has one
visible effect: an executable mapping of a pseudo-fs fd, such as a
dma-buf, now fails with -EPERM, which is the invariant the assertion
enforces. No in-tree caller maps these executable.
Reproduce on CONFIG_DEBUG_VFS=y:
make -C tools/testing/selftests/dmabuf-heaps
sudo ./tools/testing/selftests/dmabuf-heaps/dmabuf-heap -t system
libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()
Since commit 1e7ab6f67824 ("anon_inode: rework assertions"),
path_noexec() warns when an anonymous-inode file is mmap'd from a
superblock that has not set SB_I_NOEXEC. dma-buf backs its files this
way and never set the flag, so mmap of any exported buffer trips the
warning on a CONFIG_DEBUG_VFS=y kernel:
WARNING: CPU: 11 PID: 121813 at fs/exec.c:118 path_noexec+0x47/0x50
do_mmap+0x2b5/0x680
vm_mmap_pgoff+0x129/0x210
ksys_mmap_pgoff+0x177/0x240
__x64_sys_mmap+0x33/0x70
init_pseudo() sets up internal SB_NOUSER mounts that are never
path-reachable. Set both flags here so every pseudo filesystem gets
them by default instead of each caller setting them.
SB_I_NODEV is inert for unreachable mounts. SB_I_NOEXEC has one
visible effect: an executable mapping of a pseudo-fs fd, such as a
dma-buf, now fails with -EPERM, which is the invariant the assertion
enforces. No in-tree caller maps these executable.
Reproduce on CONFIG_DEBUG_VFS=y:
make -C tools/testing/selftests/dmabuf-heaps
sudo ./tools/testing/selftests/dmabuf-heaps/dmabuf-heap -t system
Published:
2026-08-06
Score:
n/a
EPSS:
< 1% Very Low
KEV:
No
Impact:
n/a
Action:
n/a
Analysis and contextual insights are available on OpenCVE Cloud.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
Sign in to view the affected projects.
Advisories
No advisories yet.
References
History
Thu, 06 Aug 2026 07:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo() Since commit 1e7ab6f67824 ("anon_inode: rework assertions"), path_noexec() warns when an anonymous-inode file is mmap'd from a superblock that has not set SB_I_NOEXEC. dma-buf backs its files this way and never set the flag, so mmap of any exported buffer trips the warning on a CONFIG_DEBUG_VFS=y kernel: WARNING: CPU: 11 PID: 121813 at fs/exec.c:118 path_noexec+0x47/0x50 do_mmap+0x2b5/0x680 vm_mmap_pgoff+0x129/0x210 ksys_mmap_pgoff+0x177/0x240 __x64_sys_mmap+0x33/0x70 init_pseudo() sets up internal SB_NOUSER mounts that are never path-reachable. Set both flags here so every pseudo filesystem gets them by default instead of each caller setting them. SB_I_NODEV is inert for unreachable mounts. SB_I_NOEXEC has one visible effect: an executable mapping of a pseudo-fs fd, such as a dma-buf, now fails with -EPERM, which is the invariant the assertion enforces. No in-tree caller maps these executable. Reproduce on CONFIG_DEBUG_VFS=y: make -C tools/testing/selftests/dmabuf-heaps sudo ./tools/testing/selftests/dmabuf-heaps/dmabuf-heap -t system | |
| Title | libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo() | |
| 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: 2026-08-06T07:13:51.523Z
Reserved: 2026-07-19T15:36:31.799Z
Link: CVE-2026-64596
No data.
No data.
No data.
OpenCVE Enrichment
Updated: 2026-08-06T10:00:05Z
Weaknesses
No weakness.