CVE-2026-53381

virtiofs: fix UAF on submount umount

State: Published
Severity: 7.8 High
Published: Jul 19, 2026
Updated: Oct 19, 2026
Reserved: Jun 9, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

virtiofs: fix UAF on submount umount

iput() called from fuse_release_end() can Oops if the super block has already been destroyed. Normally this is prevented by waiting for num_waiting to go down to zero before commencing with super block shutdown.

This only works, however, for the last submount instance, as the wait counter is per connection, not per superblock.

Revert to using synchronous release requests for the auto_submounts case, which is virtiofs only at this time.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

CWE-416 Use After Free

Affected Products

Product	Versions
LinuxLinux	548e1f2bac1d4df91a6138f26bb4ab00323fd948 to before 607a1d4c42f649e6197567c0448fd9ebb316cd42Affected cfd1aa3e2b71f3327cb373c45a897c9028c62b35 to before 1cc0e3a0c6499aaaa2f21a4fcbba388486afb25eAffected 83b375c6efef69b1066ad2d79601221e7892745a to before 0b809199ff87c44487e516a725dd4be2185712ceAffected bfd17b6138df0122a95989457d8e18ce0b86165e to before 2181a09ba980f142650fb053666350ead4471cfeAffected b26923512dbe57ae4917bafd31396d22a9d1691a to before 97c4691653d145dcc699eca5d3aba3219a520f1fAffected 26e5c67deb2e1f42a951f022fdf5b9f7eb747b01 to before 2abfd3ffbd9452f72535d96ff3982b3ab1f8f2f9Affected 26e5c67deb2e1f42a951f022fdf5b9f7eb747b01 to before 39a2b95e008665c14f84e50ed411d898df7cd11bAffected 26e5c67deb2e1f42a951f022fdf5b9f7eb747b01 to before e09412a714bcd49375198427bb4aa005037a9d6fAffected 26e5c67deb2e1f42a951f022fdf5b9f7eb747b01 to before 06b41351779e9289e8785694ade9042ae85e41eaAffected f19a1390af448d9e193c08e28ea5f727bf3c3049Affected 5.10.246 to before 5.10.260Affected 5.15.196 to before 5.15.211Affected 6.1.158 to before 6.1.177Affected 6.6.115 to before 6.6.144Affected 6.12.54 to before 6.12.95Affected 6.17.4 to before 6.18Affected
LinuxLinux	6.18Affected before 6.18Not affected 5.10.260 through 5.10.Not affected 5.15.211 through 5.15.Not affected 6.1.177 through 6.1.Not affected 6.6.144 through 6.6.Not affected 6.12.95 through 6.12.Not affected 6.18.37 through 6.18.Not affected 7.0.14 through 7.0.Not affected 7.1.2 through 7.1.Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

548e1f2bac1d4df91a6138f26bb4ab00323fd948 to before 607a1d4c42f649e6197567c0448fd9ebb316cd42Affected
cfd1aa3e2b71f3327cb373c45a897c9028c62b35 to before 1cc0e3a0c6499aaaa2f21a4fcbba388486afb25eAffected
83b375c6efef69b1066ad2d79601221e7892745a to before 0b809199ff87c44487e516a725dd4be2185712ceAffected
bfd17b6138df0122a95989457d8e18ce0b86165e to before 2181a09ba980f142650fb053666350ead4471cfeAffected
b26923512dbe57ae4917bafd31396d22a9d1691a to before 97c4691653d145dcc699eca5d3aba3219a520f1fAffected
26e5c67deb2e1f42a951f022fdf5b9f7eb747b01 to before 2abfd3ffbd9452f72535d96ff3982b3ab1f8f2f9Affected
26e5c67deb2e1f42a951f022fdf5b9f7eb747b01 to before 39a2b95e008665c14f84e50ed411d898df7cd11bAffected
26e5c67deb2e1f42a951f022fdf5b9f7eb747b01 to before e09412a714bcd49375198427bb4aa005037a9d6fAffected
26e5c67deb2e1f42a951f022fdf5b9f7eb747b01 to before 06b41351779e9289e8785694ade9042ae85e41eaAffected
f19a1390af448d9e193c08e28ea5f727bf3c3049Affected
5.10.246 to before 5.10.260Affected
5.15.196 to before 5.15.211Affected
6.1.158 to before 6.1.177Affected
6.6.115 to before 6.6.144Affected
6.12.54 to before 6.12.95Affected
6.17.4 to before 6.18Affected

LinuxLinux

6.18Affected
before 6.18Not affected
5.10.260 through 5.10.*Not affected
5.15.211 through 5.15.*Not affected
6.1.177 through 6.1.*Not affected
6.6.144 through 6.6.*Not affected
6.12.95 through 6.12.*Not affected
6.18.37 through 6.18.*Not affected
7.0.14 through 7.0.*Not affected
7.1.2 through 7.1.*Not affected
7.2 and laterNot affected

References

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