CVE-2024-56549

Description

In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix NULL pointer dereference in object->file At present, the object->file has the NULL pointer dereference problem in ondemand-mode. The root cause is that the allocated fd and object->file lifetime are inconsistent, and the user-space invocation to anon_fd uses object->file. Following is the process that triggers the issue: [write fd] [umount] cachefiles_ondemand_fd_write_iter fscache_cookie_state_machine cachefiles_withdraw_cookie if (!file) return -ENOBUFS cachefiles_clean_up_object cachefiles_unmark_inode_in_use fput(object->file) object->file = NULL // file NULL pointer dereference! __cachefiles_write(..., file, ...) Fix this issue by add an additional reference count to the object->file before write/llseek, and decrement after it finished.

Reserved 2024-12-27 | Published 2024-12-27 | Updated 2025-01-20 | Assigner Linux

Product status

Default status
unaffected

c8383054506c77b814489c09877b5db83fd4abf2 before f98770440c9bc468e2fd878212ec9526dbe08293
affected

c8383054506c77b814489c09877b5db83fd4abf2 before 9582c7664103c9043e80a78f5c382aa6bdd67418
affected

c8383054506c77b814489c09877b5db83fd4abf2 before 31ad74b20227ce6b40910ff78b1c604e42975cf1
affected

Default status
affected

5.19
affected

Any version before 5.19
unaffected

6.11.11
unaffected

6.12.2
unaffected

6.13
unaffected

References

git.kernel.org/...c/f98770440c9bc468e2fd878212ec9526dbe08293

git.kernel.org/...c/9582c7664103c9043e80a78f5c382aa6bdd67418

git.kernel.org/...c/31ad74b20227ce6b40910ff78b1c604e42975cf1

cve.org (CVE-2024-56549)

nvd.nist.gov (CVE-2024-56549)

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