cbcvebase.
CVE-2025-37999
published 2025-05-29

CVE-2025-37999: In the Linux kernel, the following vulnerability has been resolved: fs/erofs/fileio: call erofs_onlinefolio_split() after bio_add_folio() If bio_add_folio()…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.15%
4.9th percentile
In the Linux kernel, the following vulnerability has been resolved: fs/erofs/fileio: call erofs_onlinefolio_split() after bio_add_folio() If bio_add_folio() fails (because it is full), erofs_fileio_scan_folio() needs to submit the I/O request via erofs_fileio_rq_submit() and allocate a new I/O request with an empty `struct bio`. Then it retries the bio_add_folio() call. However, at this point, erofs_onlinefolio_split() has already been called which increments `folio->private`; the retry will call erofs_onlinefolio_split() again, but there will never be a matching erofs_onlinefolio_end() call. This leaves the folio locked forever and all waiters will be stuck in folio_wait_bit_common(). This bug has been added by commit ce63cb62d794 ("erofs: support unencoded inodes for fileio"), but was practically unreachable because there was room for 256 folios in the `struct bio` - until commit 9f74ae8c9ac9 ("erofs: shorten bvecs[] for file-backed mounts") which reduced the array capacity to 16 folios. It was now trivial to trigger the bug by manually invoking readahead from userspace, e.g.: posix_fadvise(fd, 0, st.st_size, POSIX_FADV_WILLNEED); This should be fixed by invoking erofs_onlinefolio_split() only after bio_add_folio() has succeeded. This is safe: asynchronous completions invoking erofs_onlinefolio_end() will not unlock the folio because erofs_fileio_scan_folio() is still holding a reference to be released by erofs_onlinefolio_end() at the end.

Affected

10 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.12.29-1 (forky)linux 6.12.29-1 (forky)
linuxlinux
linuxlinux>= ce63cb62d794c98c7631c2296fa845f2a8d0a4a1 < 61e0fc3312309867e5a3495329dad0286d2a570361e0fc3312309867e5a3495329dad0286d2a5703
linuxlinux>= ce63cb62d794c98c7631c2296fa845f2a8d0a4a1 < c26076197df348c84cc23e5962d61902e072a0f5c26076197df348c84cc23e5962d61902e072a0f5
linuxlinux>= ce63cb62d794c98c7631c2296fa845f2a8d0a4a1 < bbfe756dc3062c1e934f06e5ba39c239aa953b92bbfe756dc3062c1e934f06e5ba39c239aa953b92
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.29-16.12.29-1
linuxlinux_kernel>= 0 < 6.12.29-16.12.29-1
linuxlinux_kernel>= 6.12 < 6.12.296.12.29
linuxlinux_kernel>= 6.13 < 6.14.76.14.7

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv7.8HIGH
vendor_ubuntu7.8HIGH
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
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