{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74259","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.877Z","datePublished":"2026-08-15T05:57:36.937Z","dateUpdated":"2026-08-17T05:45:08.700Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:45:08.700Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: remove all cifs files before kill super\n\nCifs files may be put into fileinfo_put_wq during umounting cifs.\nAfter umount done, cifsFileInfo_put_final is called, which cause\nfollowing BUG:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000000\n...\n[  134.222152]  list_lru_add+0x64/0x1a0\n[  134.222399]  ? cifs_put_tcon+0x171/0x340 [cifs]\n[  134.222772]  d_lru_add+0x44/0x60\n[  134.222997]  dput+0x1fc/0x210\n[  134.223213]  cifsFileInfo_put_final+0x11a/0x140 [cifs]\n[  134.223576]  process_one_work+0x17c/0x320\n[  134.223843]  worker_thread+0x188/0x280\n[  134.224084]  ? __pfx_worker_thread+0x10/0x10\n[  134.224366]  kthread+0xcc/0x100\n[  134.224576]  ? __pfx_kthread+0x10/0x10\n[  134.224827]  ret_from_fork+0x30/0x50\n[  134.225063]  ? __pfx_kthread+0x10/0x10\n[  134.225328]  ret_from_fork_asm+0x1b/0x30\n\nThis can be reproduce by following:\nunshare -n bash -c \"\nmkdir -p ${CIFS_MNT}\nip netns attach root 1\nip link add eth0 type veth peer veth0 netns root\nip link set eth0 up\nip -n root link set veth0 up\nip addr add 192.168.0.2/24 dev eth0\nip -n root addr add 192.168.0.1/24 dev veth0\nip route add default via 192.168.0.1 dev eth0\nip netns exec root sysctl net.ipv4.ip_forward=1\nip netns exec root iptables -t nat -A POSTROUTING -s 192.168.0.2 -o\n${DEV} -j MASQUERADE\nmount -t cifs ${CIFS_PATH} ${CIFS_MNT} -o\nvers=3.0,sec=ntlmssp,credentials=${CIFS_CRED},rsize=65536,wsize=65536,cache=none,echo_interval=1\ntouch ${CIFS_MNT}/a.txt\nip netns exec root iptables -t nat -D POSTROUTING -s 192.168.0.2 -o\n${DEV} -j MASQUERADE\n\"\numount ${CIFS_MNT}"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The flaw is reached via the local CIFS client umount/teardown path (umount syscall through cifs_kill_sb/cifs_umount), not from remote SMB packet receive handling; network/server behavior only influences deferred close timing.\nAC:L - An attacker controls both sides by opening files, provoking server-close failures (malicious SMB server or induced network loss as in the repro), and triggering umount, repeatedly hitting the async workqueue race without external timing luck.\nPR:N - A malicious or compromised remote SMB/CIFS server needs no credentials or privileges on the victim host; it only needs the client to have mounted the share and later umount, while the attacker drives failing close responses over the existing session.\nUI:N - No victim interaction beyond an already-established mount is required for the malicious-server scenario; a local attacker can also self-drive mount/open/umount to trigger the bug without another user performing actions.\nS:U - Exploitation corrupts or crashes kernel memory on the same host during CIFS unmount cleanup; it does not cross VM, container, or IOMMU security boundaries.\nC:H - cifsFileInfo_put_final() dereferences dentry, inode, and cifsInodeInfo after kill_anon_super() destroyed the superblock, constituting use-after-free that can expose adjacent kernel heap contents beyond the observed NULL dereference.\nI:H - Post-teardown cifsFileInfo_put_final() performs list_del, lock teardown, and kfree on potentially freed cinode/file structures, enabling heap corruption and potential control-flow hijack primitives typical of kernel UAF bugs.\nA:H - The bug produces a kernel NULL pointer dereference/oops in list_lru_add during dentry LRU insertion in the fileinfo_put_wq worker, reliably crashing or destabilizing the host when triggered."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/connect.c"],"versions":[{"version":"708c276f516d27beaded7f372ac8111cee43926c","lessThan":"55fb9581986141659002264fdc75cef307811eb8","status":"affected","versionType":"git"},{"version":"0629a1a187e424373364d681b42b101894bdb548","lessThan":"4465ebe67d89345954bb3622b25dd13e06f9d367","status":"affected","versionType":"git"},{"version":"0e4b8faaaebe3137bec5723ef2b3cb0437fb38fd","lessThan":"3baedc9b2f53e6a6ac57b16fdff0f9b954d9ca71","status":"affected","versionType":"git"},{"version":"f655467a9973f964b267871e5fef533ad5014494","lessThan":"21303c4a2b7275e626c6b67de0f45f2d5b9bb3e7","status":"affected","versionType":"git"},{"version":"340cea84f691c5206561bb2e0147158fe02070be","lessThan":"7839f1817a0cb6c4ed5cfe25d04845c43380a129","status":"affected","versionType":"git"},{"version":"340cea84f691c5206561bb2e0147158fe02070be","lessThan":"6d9a4aaaa8b2612b5ef9d581e2f286a458b71ee1","status":"affected","versionType":"git"},{"version":"30afc6ea72cc6cf7c8d579e79b64232801c38d08","status":"affected","versionType":"git"},{"version":"6.1.167","lessThan":"6.1.178","status":"affected","versionType":"semver"},{"version":"6.6.130","lessThan":"6.6.145","status":"affected","versionType":"semver"},{"version":"6.12.78","lessThan":"6.12.97","status":"affected","versionType":"semver"},{"version":"6.18.20","lessThan":"6.18.40","status":"affected","versionType":"semver"},{"version":"6.19.10","lessThan":"6.20","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/connect.c"],"versions":[{"version":"7.0","status":"affected"},{"version":"0","lessThan":"7.0","status":"unaffected","versionType":"semver"},{"version":"6.1.178","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.145","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.97","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.40","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.5","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","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":"6.1.167","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.130","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.78","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18.20","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19.10"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/55fb9581986141659002264fdc75cef307811eb8"},{"url":"https://git.kernel.org/stable/c/4465ebe67d89345954bb3622b25dd13e06f9d367"},{"url":"https://git.kernel.org/stable/c/3baedc9b2f53e6a6ac57b16fdff0f9b954d9ca71"},{"url":"https://git.kernel.org/stable/c/21303c4a2b7275e626c6b67de0f45f2d5b9bb3e7"},{"url":"https://git.kernel.org/stable/c/7839f1817a0cb6c4ed5cfe25d04845c43380a129"},{"url":"https://git.kernel.org/stable/c/6d9a4aaaa8b2612b5ef9d581e2f286a458b71ee1"}],"title":"cifs: remove all cifs files before kill super","x_generator":{"engine":"bippy-1.2.0"}}}}