Description
In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY filemap_fault() may drop the mmap_lock before returning VM_FAULT_RETRY, as documented in mm/filemap.c: "If our return value has VM_FAULT_RETRY set, it's because the mmap_lock may be dropped before doing I/O or by lock_folio_maybe_drop_mmap()." When this happens, a concurrent munmap() can call remove_vma() and free the vm_area_struct via RCU. The saved 'vma' pointer in ocfs2_fault() then becomes a dangling pointer, and the subsequent trace_ocfs2_fault() call dereferences it -- a use-after-free. Fix this by saving ip_blkno as a plain integer before calling filemap_fault(), and removing vma from the trace event. Since ip_blkno is copied by value before the lock can be dropped, it remains valid regardless of what happens to the vma or inode afterward.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
614a9e849ca6ea24843795251cb30af525d5336b to < 36539c4d536f851a3b346a6ebb27b51bc3d77a94affected614a9e849ca6ea24843795251cb30af525d5336b to < 35c2c05261d6f6d84aaa1355afa201d507943e76affected614a9e849ca6ea24843795251cb30af525d5336b to < 3f5e74b5db9353b01ed50f4de84e75b755f8fbc2affected614a9e849ca6ea24843795251cb30af525d5336b to < 6f072daefcab1d84ce37c073645615f63be91006affected614a9e849ca6ea24843795251cb30af525d5336b to < 4cf2768a0291a0cdd0dae801ea0eafa3878a349daffected614a9e849ca6ea24843795251cb30af525d5336b to < d45ff441b416d4aa1af72b1db23d959601c04da2affected614a9e849ca6ea24843795251cb30af525d5336b to < 76a602fdbb78dd05b2da06f74a988cebc97e82d0affected614a9e849ca6ea24843795251cb30af525d5336b to < 925bf22c1b823e231b1baea761fe8a1512e442f2affected614a9e849ca6ea24843795251cb30af525d5336b to < 7de554cabf160e331e4442e2a9ad874ca9875921affected
Linux Linux
Default version status: affected
2.6.39affected0 to < 2.6.39unaffected5.10.258 to ≤ 5.10.*unaffected5.15.209 to ≤ 5.15.*unaffected6.1.175 to ≤ 6.1.*unaffected6.6.136 to ≤ 6.6.*unaffected6.12.83 to ≤ 6.12.*unaffected6.18.24 to ≤ 6.18.*unaffected6.19.14 to ≤ 6.19.*unaffected7.0.1 to ≤ 7.0.*unaffected7.1 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/36539c4d536f851a3b346a6ebb27b51bc3d77a94 ↗
- https://git.kernel.org/stable/c/35c2c05261d6f6d84aaa1355afa201d507943e76 ↗
- https://git.kernel.org/stable/c/3f5e74b5db9353b01ed50f4de84e75b755f8fbc2 ↗
- https://git.kernel.org/stable/c/6f072daefcab1d84ce37c073645615f63be91006 ↗
- https://git.kernel.org/stable/c/4cf2768a0291a0cdd0dae801ea0eafa3878a349d ↗
- https://git.kernel.org/stable/c/d45ff441b416d4aa1af72b1db23d959601c04da2 ↗
- https://git.kernel.org/stable/c/76a602fdbb78dd05b2da06f74a988cebc97e82d0 ↗
- https://git.kernel.org/stable/c/925bf22c1b823e231b1baea761fe8a1512e442f2 ↗
- https://git.kernel.org/stable/c/7de554cabf160e331e4442e2a9ad874ca9875921 ↗