CVE-2025-38710
In the Linux kernel, the following vulnerability has been resolved: gfs2: Validate i_depth for exhash directories A fuzzer test introduced corruption that ends up with a depth of 0 in dir_e_read(), causing an undefined shift by 32 at: index = hash >>…
Does this matter?
Lower severity and a low EPSS score (0.15%). Track it; it rarely justifies an emergency change on its own.
Description
In the Linux kernel, the following vulnerability has been resolved: gfs2: Validate i_depth for exhash directories A fuzzer test introduced corruption that ends up with a depth of 0 in dir_e_read(), causing an undefined shift by 32 at: index = hash >> (32 - dip->i_depth); As calculated in an open-coded way in dir_make_exhash(), the minimum depth for an exhash directory is ilog2(sdp->sd_hash_ptrs) and 0 is invalid as sdp->sd_hash_ptrs is fixed as sdp->bsize / 16 at mount time. So we can avoid the undefined behaviour by checking for depth values lower than the minimum in gfs2_dinode_in(). Values greater than the maximum are already being checked for there. Also switch the calculation in dir_make_exhash() to use ilog2() to clarify how the depth is calculated. Tested with the syzkaller repro.c and xfstests '-g quick'.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.15% probability · 5th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/076e992752e4b24178918f748d75597c80a408d2
- https://git.kernel.org/stable/c/112bb60cd0e254a369e95aa9941a694ffeca089f
- https://git.kernel.org/stable/c/366183911b153e9b8cf758e1414e1154d7569337
- https://git.kernel.org/stable/c/53a0249d68a210c16e961b83adfa82f94ee0a53dPatch
- https://git.kernel.org/stable/c/557c024ca7250bb65ae60f16c02074106c2f197bPatch
- https://git.kernel.org/stable/c/9680c58675b82348ab84d387e4fa727f7587e1a0Patch
- https://git.kernel.org/stable/c/b5f46951e62377b6e406fadc18bc3c5bdf1632a7Patch
- https://git.kernel.org/stable/c/cddea0c721106ea480371412d8de21705eb27376
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.