{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-40237", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.181Z", "datePublished": "2025-12-04T15:31:27.325Z", "dateUpdated": "2025-12-04T15:31:27.325Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-12-04T15:31:27.325Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/notify: call exportfs_encode_fid with s_umount\n\nCalling intotify_show_fdinfo() on fd watching an overlayfs inode, while\nthe overlayfs is being unmounted, can lead to dereferencing NULL ptr.\n\nThis issue was found by syzkaller.\n\nRace Condition Diagram:\n\nThread 1 Thread 2\n-------- --------\n\ngeneric_shutdown_super()\n shrink_dcache_for_umount\n sb->s_root = NULL\n\n |\n | vfs_read()\n | inotify_fdinfo()\n | * inode get from mark *\n | show_mark_fhandle(m, inode)\n | exportfs_encode_fid(inode, ..)\n | ovl_encode_fh(inode, ..)\n | ovl_check_encode_origin(inode)\n | * deref i_sb->s_root *\n |\n |\n v\n fsnotify_sb_delete(sb)\n\nWhich then leads to:\n\n[ 32.133461] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI\n[ 32.134438] KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]\n[ 32.135032] CPU: 1 UID: 0 PID: 4468 Comm: systemd-coredum Not tainted 6.17.0-rc6 #22 PREEMPT(none)\n\n<snip registers, unreliable trace>\n\n[ 32.143353] Call Trace:\n[ 32.143732] ovl_encode_fh+0xd5/0x170\n[ 32.144031] exportfs_encode_inode_fh+0x12f/0x300\n[ 32.144425] show_mark_fhandle+0xbe/0x1f0\n[ 32.145805] inotify_fdinfo+0x226/0x2d0\n[ 32.146442] inotify_show_fdinfo+0x1c5/0x350\n[ 32.147168] seq_show+0x530/0x6f0\n[ 32.147449] seq_read_iter+0x503/0x12a0\n[ 32.148419] seq_read+0x31f/0x410\n[ 32.150714] vfs_read+0x1f0/0x9e0\n[ 32.152297] ksys_read+0x125/0x240\n\nIOW ovl_check_encode_origin derefs inode->i_sb->s_root, after it was set\nto NULL in the unmount path.\n\nFix it by protecting calling exportfs_encode_fid() from\nshow_mark_fhandle() with s_umount lock.\n\nThis form of fix was suggested by Amir in [1].\n\n[1]: https://lore.kernel.org/all/CAOQ4uxhbDwhb+2Brs1UdkoF0a3NSdBAOQPNfEHjahrgoKJpLEw@mail.gmail.com/"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/notify/fdinfo.c"], "versions": [{"version": "f0c0ac84de17c37e6e84da65fb920f91dada55ad", "lessThan": "bc1c6b803e14ea2b8f7e33b7164013f666ceb656", "status": "affected", "versionType": "git"}, {"version": "3c7c90274ae339e1ad443c9be1c67a20b80b9c76", "lessThan": "3f307a9f7a7a2822e38ac451b73e2244e7279496", "status": "affected", "versionType": "git"}, {"version": "c45beebfde34aa71afbc48b2c54cdda623515037", "lessThan": "d1894bc542becb0fda61e7e513b09523cab44030", "status": "affected", "versionType": "git"}, {"version": "c45beebfde34aa71afbc48b2c54cdda623515037", "lessThan": "a7c4bb43bfdc2b9f06ee9d036028ed13a83df42a", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/notify/fdinfo.c"], "versions": [{"version": "6.13", "status": "affected"}, {"version": "0", "lessThan": "6.13", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.115", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.56", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17.6", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.74", "versionEndExcluding": "6.6.115"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.10", "versionEndExcluding": "6.12.56"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.17.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/bc1c6b803e14ea2b8f7e33b7164013f666ceb656"}, {"url": "https://git.kernel.org/stable/c/3f307a9f7a7a2822e38ac451b73e2244e7279496"}, {"url": "https://git.kernel.org/stable/c/d1894bc542becb0fda61e7e513b09523cab44030"}, {"url": "https://git.kernel.org/stable/c/a7c4bb43bfdc2b9f06ee9d036028ed13a83df42a"}], "title": "fs/notify: call exportfs_encode_fid with s_umount", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/notify: call exportfs_encode_fid with s_umount\n\nCalling intotify_show_fdinfo() on fd watching an overlayfs inode, while\nthe overlayfs is being unmounted, can lead to dereferencing NULL ptr.\n\nThis issue was found by syzkaller.\n\nRace Condition Diagram:\n\nThread 1 Thread 2\n-------- --------\n\ngeneric_shutdown_super()\n shrink_dcache_for_umount\n sb->s_root = NULL\n\n |\n | vfs_read()\n | inotify_fdinfo()\n | * inode get from mark *\n | show_mark_fhandle(m, inode)\n | exportfs_encode_fid(inode, ..)\n | ovl_encode_fh(inode, ..)\n | ovl_check_encode_origin(inode)\n | * deref i_sb->s_root *\n |\n |\n v\n fsnotify_sb_delete(sb)\n\nWhich then leads to:\n\n[ 32.133461] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI\n[ 32.134438] KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]\n[ 32.135032] CPU: 1 UID: 0 PID: 4468 Comm: systemd-coredum Not tainted 6.17.0-rc6 #22 PREEMPT(none)\n\n<snip registers, unreliable trace>\n\n[ 32.143353] Call Trace:\n[ 32.143732] ovl_encode_fh+0xd5/0x170\n[ 32.144031] exportfs_encode_inode_fh+0x12f/0x300\n[ 32.144425] show_mark_fhandle+0xbe/0x1f0\n[ 32.145805] inotify_fdinfo+0x226/0x2d0\n[ 32.146442] inotify_show_fdinfo+0x1c5/0x350\n[ 32.147168] seq_show+0x530/0x6f0\n[ 32.147449] seq_read_iter+0x503/0x12a0\n[ 32.148419] seq_read+0x31f/0x410\n[ 32.150714] vfs_read+0x1f0/0x9e0\n[ 32.152297] ksys_read+0x125/0x240\n\nIOW ovl_check_encode_origin derefs inode->i_sb->s_root, after it was set\nto NULL in the unmount path.\n\nFix it by protecting calling exportfs_encode_fid() from\nshow_mark_fhandle() with s_umount lock.\n\nThis form of fix was suggested by Amir in [1].\n\n[1]: https://lore.kernel.org/all/CAOQ4uxhbDwhb+2Brs1UdkoF0a3NSdBAOQPNfEHjahrgoKJpLEw@mail.gmail.com/"}], "id": "CVE-2025-40237", "lastModified": "2025-12-04T17:15:08.283", "metrics": {}, "published": "2025-12-04T16:16:16.697", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3f307a9f7a7a2822e38ac451b73e2244e7279496"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a7c4bb43bfdc2b9f06ee9d036028ed13a83df42a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bc1c6b803e14ea2b8f7e33b7164013f666ceb656"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d1894bc542becb0fda61e7e513b09523cab44030"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: fs/notify: call exportfs_encode_fid with s_umount", "id": "2418829", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2418829"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nfs/notify: call exportfs_encode_fid with s_umount\nCalling intotify_show_fdinfo() on fd watching an overlayfs inode, while\nthe overlayfs is being unmounted, can lead to dereferencing NULL ptr.\nThis issue was found by syzkaller.\nRace Condition Diagram:\nThread 1 Thread 2\n-------- --------\ngeneric_shutdown_super()\nshrink_dcache_for_umount\nsb->s_root = NULL\n|\n| vfs_read()\n| inotify_fdinfo()\n| * inode get from mark *\n| show_mark_fhandle(m, inode)\n| exportfs_encode_fid(inode, ..)\n| ovl_encode_fh(inode, ..)\n| ovl_check_encode_origin(inode)\n| * deref i_sb->s_root *\n|\n|\nv\nfsnotify_sb_delete(sb)\nWhich then leads to:\n[ 32.133461] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI\n[ 32.134438] KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]\n[ 32.135032] CPU: 1 UID: 0 PID: 4468 Comm: systemd-coredum Not tainted 6.17.0-rc6 #22 PREEMPT(none)\n<snip registers, unreliable trace>\n[ 32.143353] Call Trace:\n[ 32.143732] ovl_encode_fh+0xd5/0x170\n[ 32.144031] exportfs_encode_inode_fh+0x12f/0x300\n[ 32.144425] show_mark_fhandle+0xbe/0x1f0\n[ 32.145805] inotify_fdinfo+0x226/0x2d0\n[ 32.146442] inotify_show_fdinfo+0x1c5/0x350\n[ 32.147168] seq_show+0x530/0x6f0\n[ 32.147449] seq_read_iter+0x503/0x12a0\n[ 32.148419] seq_read+0x31f/0x410\n[ 32.150714] vfs_read+0x1f0/0x9e0\n[ 32.152297] ksys_read+0x125/0x240\nIOW ovl_check_encode_origin derefs inode->i_sb->s_root, after it was set\nto NULL in the unmount path.\nFix it by protecting calling exportfs_encode_fid() from\nshow_mark_fhandle() with s_umount lock.\nThis form of fix was suggested by Amir in [1].\n[1]: https://lore.kernel.org/all/CAOQ4uxhbDwhb+2Brs1UdkoF0a3NSdBAOQPNfEHjahrgoKJpLEw@mail.gmail.com/"], "name": "CVE-2025-40237", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-12-04T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-40237\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-40237\nhttps://lore.kernel.org/linux-cve-announce/2025120402-CVE-2025-40237-f087@gregkh/T"], "threat_severity": "Moderate"}