In the Linux kernel, the following vulnerability has been resolved:
cifs: Release folio lock on fscache read hit.
Under the current code, when cifs_readpage_worker is called, the call
contract is that the callee should unlock the page. This is documented
in the read_folio section of Documentation/filesystems/vfs.rst as:
> The filesystem should unlock the folio once the read has completed,
> whether it was successful or not.
Without this change, when fscache is in use and cache hit occurs during
a read, the page lock is leaked, producing the following stack on
subsequent reads (via mmap) to the page:
$ cat /proc/3890/task/12864/stack
[<0>] folio_wait_bit_common+0x124/0x350
[<0>] filemap_read_folio+0xad/0xf0
[<0>] filemap_fault+0x8b1/0xab0
[<0>] __do_fault+0x39/0x150
[<0>] do_fault+0x25c/0x3e0
[<0>] __handle_mm_fault+0x6ca/0xc70
[<0>] handle_mm_fault+0xe9/0x350
[<0>] do_user_addr_fault+0x225/0x6c0
[<0>] exc_page_fault+0x84/0x1b0
[<0>] asm_exc_page_fault+0x27/0x30
This requires a reboot to resolve; it is a deadlock.
Note however that the call to cifs_readpage_from_fscache does mark the
page clean, but does not free the folio lock. This happens in
__cifs_readpage_from_fscache on success. Releasing the lock at that
point however is not appropriate as cifs_readahead also calls
cifs_readpage_from_fscache and *does* unconditionally release the lock
after its return. This change therefore effectively makes
cifs_readpage_worker work like cifs_readahead.
References
Configurations
Configuration 1 (hide)
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History
No history.
Information
Published : 2025-10-04 16:15
Updated : 2026-03-21 00:51
NVD link : CVE-2023-53593
Mitre link : CVE-2023-53593
CVE.ORG link : CVE-2023-53593
JSON object : View
Products Affected
linux
- linux_kernel
CWE