CVE-2026-45960hfsplus: return error when node already exists in hfs_bnode_create

Official description

In the Linux kernel, the following vulnerability has been resolved: hfsplus: return error when node already exists in hfs_bnode_create When hfs_bnode_create() finds that a node is already hashed (which should not happen in normal operation), it currently returns the existing node without incrementing its reference count. This causes a reference count inconsistency that leads to a kernel panic when the node is later freed in hfs_bnode_put(): kernel BUG at fs/hfsplus/bnode.c:676! BUG_ON(!atomic_read(&node->refcnt)) This scenario can occur when hfs_bmap_alloc() attempts to allocate a node that is already in use (e.g., when node 0's bitmap bit is incorrectly unset), or due to filesystem corruption. Returning an existing node from a create path is not normal operation. Fix this by returning ERR_PTR(-EEXIST) instead of the node when it's already hashed. This properly signals the error condition to callers, which already check for IS_ERR() return values.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/1ca428769cb4737a25bd32fb4d1573cc09eeaeef
• https://git.kernel.org/stable/c/507a1de58c21c95ad7c44afccaf1222d1c42246b
• https://git.kernel.org/stable/c/986455135b95f32c1f142068e451098fc751749e
• https://git.kernel.org/stable/c/7b57ada854b32310f224abd61bcfec2d5790ff0a
• https://git.kernel.org/stable/c/51838112d9c22502333c3085ca0c0d691e7093c6
• https://git.kernel.org/stable/c/2e6ff6a6fc69cc17ed10c9cb6242935d52acd52d
• https://git.kernel.org/stable/c/2e9185a42e0e237c74435fd092b7c34537c62156
• https://git.kernel.org/stable/c/d8a73cc46c8462a969a7516131feb3096f4c49d3