CVE-2021-47507

nfsd: Fix nsfd startup race (again)

State: Published
Severity: Not scored
Published: May 24, 2024
Updated: May 23, 2026
Reserved: May 22, 2024

Description

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

nfsd: Fix nsfd startup race (again)

Commit bd5ae9288d64 ("nfsd: register pernet ops last, unregister first") has re-opened rpc_pipefs_event() race against nfsd_net_id registration (register_pernet_subsys()) which has been fixed by commit bb7ffbf29e76 ("nfsd: fix nsfd startup race triggering BUG_ON").

Restore the order of register_pernet_subsys() vs register_cld_notifier(). Add WARN_ON() to prevent a future regression.

Crash info: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000012 CPU: 8 PID: 345 Comm: mount Not tainted 5.4.144-... #1 pc : rpc_pipefs_event+0x54/0x120 [nfsd] lr : rpc_pipefs_event+0x48/0x120 [nfsd] Call trace: rpc_pipefs_event+0x54/0x120 [nfsd] blocking_notifier_call_chain rpc_fill_super get_tree_keyed rpc_fs_get_tree vfs_get_tree do_mount ksys_mount __arm64_sys_mount el0_svc_handler el0_svc

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	8677e99150b0830d29cc1318b4cc559e176940bb to before f5734b1714ca355703e9ea8fb61d04beff1790b9Affected 7c7cb07d4affcf41749234fe9dc4d90cd3959e32 to before c520943a00ad5015704969ad3304c956bcd49d25Affected bd5ae9288d6451bd346a1b4a59d4fe7e62ba29b7 to before 8bf902fee5893cfc2f04a698abab47629699ae9aAffected bd5ae9288d6451bd346a1b4a59d4fe7e62ba29b7 to before b10252c7ae9c9d7c90552f88b544a44ee773af64Affected 4d41f65efeec0a6da6088341203c81e49ebfcd90Affected 5.4.102 to before 5.4.165Affected 5.10.20 to before 5.10.85Affected 5.11.3 to before 5.12Affected
LinuxLinux	5.12Affected before 5.12Not affected 5.4.165 through 5.4.Not affected 5.10.85 through 5.10.Not affected 5.15.8 through 5.15.*Not affected 5.16 and laterNot affected

Product

Versions

LinuxLinux

8677e99150b0830d29cc1318b4cc559e176940bb to before f5734b1714ca355703e9ea8fb61d04beff1790b9Affected
7c7cb07d4affcf41749234fe9dc4d90cd3959e32 to before c520943a00ad5015704969ad3304c956bcd49d25Affected
bd5ae9288d6451bd346a1b4a59d4fe7e62ba29b7 to before 8bf902fee5893cfc2f04a698abab47629699ae9aAffected
bd5ae9288d6451bd346a1b4a59d4fe7e62ba29b7 to before b10252c7ae9c9d7c90552f88b544a44ee773af64Affected
4d41f65efeec0a6da6088341203c81e49ebfcd90Affected
5.4.102 to before 5.4.165Affected
5.10.20 to before 5.10.85Affected
5.11.3 to before 5.12Affected

LinuxLinux

5.12Affected
before 5.12Not affected
5.4.165 through 5.4.*Not affected
5.10.85 through 5.10.*Not affected
5.15.8 through 5.15.*Not affected
5.16 and laterNot affected

References

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