Description (CNA)
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
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 1e7ab6f67824343ee3e96f100f0937c393749a8a before b9d45d328fcda4f0d3d281b7d6f12d3f181d9381; affected 1e7ab6f67824343ee3e96f100f0937c393749a8a before 8e931557b317f0fb414839fa51fae1d5feb0ad97; affected 1e7ab6f67824343ee3e96f100f0937c393749a8a before 6de2aeffabaafaeda819e60ec8d04f199711e11a; affected 9b8076a9404568d6cb6673b9a079558b15051966; affected 6.15.6 before 6.16 |
| Linux / Linux | affected 6.16; unaffected 0 before 6.16; unaffected 6.18.39 through 6.18.*; unaffected 7.1.4 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.