{"id":"CVE-2026-31597","state":"PUBLISHED","title":"ocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY\n\nfilemap_fault() may drop the mmap_lock before returning VM_FAULT_RETRY,\nas documented in mm/filemap.c:\n\n  \"If our return value has VM_FAULT_RETRY set, it's because the mmap_lock\n  may be dropped before doing I/O or by lock_folio_maybe_drop_mmap().\"\n\nWhen this happens, a concurrent munmap() can call remove_vma() and free\nthe vm_area_struct via RCU. The saved 'vma' pointer in ocfs2_fault() then\nbecomes a dangling pointer, and the subsequent trace_ocfs2_fault() call\ndereferences it -- a use-after-free.\n\nFix this by saving ip_blkno as a plain integer before calling\nfilemap_fault(), and removing vma from the trace event. Since\nip_blkno is copied by value before the lock can be dropped, it\nremains valid regardless of what happens to the vma or inode\nafterward.","publishedAt":"2026-04-24T14:42:22.655Z","updatedAt":"2026-08-05T12:23:41.347Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"36539c4d536f851a3b346a6ebb27b51bc3d77a94","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"35c2c05261d6f6d84aaa1355afa201d507943e76","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"3f5e74b5db9353b01ed50f4de84e75b755f8fbc2","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"6f072daefcab1d84ce37c073645615f63be91006","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"4cf2768a0291a0cdd0dae801ea0eafa3878a349d","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"d45ff441b416d4aa1af72b1db23d959601c04da2","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"76a602fdbb78dd05b2da06f74a988cebc97e82d0","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"925bf22c1b823e231b1baea761fe8a1512e442f2","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"7de554cabf160e331e4442e2a9ad874ca9875921","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/mmap.c","fs/ocfs2/ocfs2_trace.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.39","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.39","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.136","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.83","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.24","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.14","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0.1","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/mmap.c","fs/ocfs2/ocfs2_trace.h"]}],"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"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31597.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31597","state":"PUBLISHED","datePublished":"2026-04-24T14:42:22.655Z","dateUpdated":"2026-08-05T12:23:41.347Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.121Z"},"containers":{"cna":{"title":"ocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY\n\nfilemap_fault() may drop the mmap_lock before returning VM_FAULT_RETRY,\nas documented in mm/filemap.c:\n\n  \"If our return value has VM_FAULT_RETRY set, it's because the mmap_lock\n  may be dropped before doing I/O or by lock_folio_maybe_drop_mmap().\"\n\nWhen this happens, a concurrent munmap() can call remove_vma() and free\nthe vm_area_struct via RCU. The saved 'vma' pointer in ocfs2_fault() then\nbecomes a dangling pointer, and the subsequent trace_ocfs2_fault() call\ndereferences it -- a use-after-free.\n\nFix this by saving ip_blkno as a plain integer before calling\nfilemap_fault(), and removing vma from the trace event. Since\nip_blkno is copied by value before the lock can be dropped, it\nremains valid regardless of what happens to the vma or inode\nafterward."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"36539c4d536f851a3b346a6ebb27b51bc3d77a94","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"35c2c05261d6f6d84aaa1355afa201d507943e76","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"3f5e74b5db9353b01ed50f4de84e75b755f8fbc2","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"6f072daefcab1d84ce37c073645615f63be91006","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"4cf2768a0291a0cdd0dae801ea0eafa3878a349d","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"d45ff441b416d4aa1af72b1db23d959601c04da2","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"76a602fdbb78dd05b2da06f74a988cebc97e82d0","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"925bf22c1b823e231b1baea761fe8a1512e442f2","versionType":"git"},{"version":"614a9e849ca6ea24843795251cb30af525d5336b","status":"affected","lessThan":"7de554cabf160e331e4442e2a9ad874ca9875921","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/mmap.c","fs/ocfs2/ocfs2_trace.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.39","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.39","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.136","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.83","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.24","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.14","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0.1","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/mmap.c","fs/ocfs2/ocfs2_trace.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/36539c4d536f851a3b346a6ebb27b51bc3d77a94"},{"url":"https://git.kernel.org/stable/c/35c2c05261d6f6d84aaa1355afa201d507943e76"},{"url":"https://git.kernel.org/stable/c/3f5e74b5db9353b01ed50f4de84e75b755f8fbc2"},{"url":"https://git.kernel.org/stable/c/6f072daefcab1d84ce37c073645615f63be91006"},{"url":"https://git.kernel.org/stable/c/4cf2768a0291a0cdd0dae801ea0eafa3878a349d"},{"url":"https://git.kernel.org/stable/c/d45ff441b416d4aa1af72b1db23d959601c04da2"},{"url":"https://git.kernel.org/stable/c/76a602fdbb78dd05b2da06f74a988cebc97e82d0"},{"url":"https://git.kernel.org/stable/c/925bf22c1b823e231b1baea761fe8a1512e442f2"},{"url":"https://git.kernel.org/stable/c/7de554cabf160e331e4442e2a9ad874ca9875921"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable path is reached by local user memory-management operations on an OCFS2 regular file mapping, via mmap/page fault and concurrent unmap. It is not directly reachable from network packets or adjacent/physical interfaces.\nAC:L - The attacker can control the relevant mmap, page fault, and munmap activity from their own process or cooperating threads. The VM_FAULT_RETRY window is a normal retry path where filemap_fault() may drop mmap_lock, so the race is attacker-repeatable.\nPR:L - A basic local user with permission to open and mmap a file on an already-mounted OCFS2 filesystem can reach ocfs2_fault(); no kernel capability is needed for the fault/unmap path. Mounting OCFS2 itself is privileged, but a reasonable OCFS2 deployment already has the filesystem mounted.\nUI:N - Exploitation does not require a separate victim action after the attacker has local access. The attacker triggers the mmap, page fault, and munmap operations directly.\nS:U - The vulnerability is in kernel filesystem/MM handling and impacts the same kernel security authority. This is standard local kernel compromise/DoS territory, not a cross-scope VM or sandbox boundary by itself.\nC:H - This is a kernel heap use-after-free of a vm_area_struct after mmap_lock can be dropped and the VMA freed. Under the stated kernel guidance, use-after-free bugs are scored High for confidentiality because freed object reuse can enable kernel memory disclosure.\nI:H - Although the observed KASAN report is a UAF read, it is still a dangling kernel heap object use in attacker-influenced VMA lifetime/reuse conditions. Under the stated guidance and uncertainty rule, UAF memory corruption is scored High for integrity.\nA:H - The bug has a demonstrated KASAN slab-use-after-free in ocfs2_fault() and can crash/oops the kernel. Kernel crash availability impact is High."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:23:41.347Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.6.136"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.12.83"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.18.24"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.19.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"7.0.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}