CVE intelligence and bounded remediation

CVE-2024-50229 — Linux Linux Kernel security vulnerability

Medium CVSS 5.5

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential deadlock with newly created symlinks Syzbot reported that page_symlink(), called by nilfs_symlink(), triggers memory reclamation involving the filesystem layer, which can result in circular lock dependencies among the reader/writer semaphore nilfs->ns_segctor_sem, s_writers percpu_rwsem (intwrite) and the fs_reclaim pseudo lock. This is because after commit 21fc61c73c39 ("don't put symlink bodies in pagecache into highmem"), the gfp flags of the page cache for symbolic links are overwritten to GFP_KERNEL via inode_nohighmem(). This is not a problem for symlinks read from the backing device, because the __GFP_FS flag is dropped after inode_nohighmem() is called. However, when a new symlink is created with nilfs_symlink(), the gfp flags remain overwritten to GFP_KERNEL. Then, memory allocation called from page_symlink() etc. triggers memory reclamation including the FS layer, which may call nilfs_evict_inode() or nilfs_dirty_inode(). And these can cause a deadlock if they are called while nilfs->ns_segctor_sem is held: Fix this issue by dropping the __GFP_FS flag from the page cache GFP flags o…

Severity
Medium
CVSS
5.5 (3.1)
Published
2024-11-09
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-667

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 4.4.116
  • linux / linux_kernel / 6.12

Showing 3 representative product identities from 13 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Race condition, TOCTOU, and lifecycle synchronization

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map concurrent actors, shared state, lock boundaries, signals, callbacks, retries, and check-then-use sequences in the affected path.
  • Determine whether untrusted users can influence timing, object names, filesystem state, or repeated state transitions.
  • Identify clustered and multi-process behavior that repository-local tests may not represent.

Remediate safely

  • Make the sensitive state transition atomic or protect it with a consistently ordered synchronization primitive.
  • Perform authorization and invariant checks on the same authoritative object and transaction used for the operation.
  • Use unique private resources, safe ownership transfer, and idempotent operations; add deterministic concurrency regression tests.

Authoritative sources

Complete CVE record and remediation plan

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