{"id":"CVE-2025-38710","title":"gfs2: Validate i_depth for exhash directories","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ngfs2: Validate i_depth for exhash directories\n\nA fuzzer test introduced corruption that ends up with a depth of 0 in\ndir_e_read(), causing an undefined shift by 32 at:\n…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 076e992752e4b24178918f748d75597c80a408d2","Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 366183911b153e9b8cf758e1414e1154d7569337","Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 112bb60cd0e254a369e95aa9941a694ffeca089f","Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < cddea0c721106ea480371412d8de21705eb27376","Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 53a0249d68a210c16e961b83adfa82f94ee0a53d","Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < b5f46951e62377b6e406fadc18bc3c5bdf1632a7","Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 9680c58675b82348ab84d387e4fa727f7587e1a0","Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 557c024ca7250bb65ae60f16c02074106c2f197b","Linux 2.6.26"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T21:52:51.698031Z"},"published":"2025-09-04","updated":"2026-10-15","sourceUpdated":"2026-10-15T22:02:28.235Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-38710","references":[{"url":"https://git.kernel.org/stable/c/076e992752e4b24178918f748d75597c80a408d2"},{"url":"https://git.kernel.org/stable/c/366183911b153e9b8cf758e1414e1154d7569337"},{"url":"https://git.kernel.org/stable/c/112bb60cd0e254a369e95aa9941a694ffeca089f"},{"url":"https://git.kernel.org/stable/c/cddea0c721106ea480371412d8de21705eb27376"},{"url":"https://git.kernel.org/stable/c/53a0249d68a210c16e961b83adfa82f94ee0a53d"},{"url":"https://git.kernel.org/stable/c/b5f46951e62377b6e406fadc18bc3c5bdf1632a7"},{"url":"https://git.kernel.org/stable/c/9680c58675b82348ab84d387e4fa727f7587e1a0"},{"url":"https://git.kernel.org/stable/c/557c024ca7250bb65ae60f16c02074106c2f197b"}],"tags":["cve.org"],"epss":0.00158,"epssPercentile":0.04903,"ingestedAt":"2026-10-15T22:48:25.520Z","slug":"CVE-2025-38710","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ngfs2: Validate i_depth for exhash directories\n\nA fuzzer test introduced corruption that ends up with a depth of 0 in\ndir_e_read(), causing an undefined shift by 32 at:\n\n  index = hash >> (32 - dip->i_depth);\n\nAs calculated in an open-coded way in dir_make_exhash(), the minimum\ndepth for an exhash directory is ilog2(sdp->sd_hash_ptrs) and 0 is\ninvalid as sdp->sd_hash_ptrs is fixed as sdp->bsize / 16 at mount time.\n\nSo we can avoid the undefined behaviour by checking for depth values\nlower than the minimum in gfs2_dinode_in(). Values greater than the\nmaximum are already being checked for there.\n\nAlso switch the calculation in dir_make_exhash() to use ilog2() to\nclarify how the depth is calculated.\n\nTested with the syzkaller repro.c and xfstests '-g quick'.\n\n## Affected\n\n- `Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 076e992752e4b24178918f748d75597c80a408d2`\n- `Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 366183911b153e9b8cf758e1414e1154d7569337`\n- `Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 112bb60cd0e254a369e95aa9941a694ffeca089f`\n- `Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < cddea0c721106ea480371412d8de21705eb27376`\n- `Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 53a0249d68a210c16e961b83adfa82f94ee0a53d`\n- `Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < b5f46951e62377b6e406fadc18bc3c5bdf1632a7`\n- `Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 9680c58675b82348ab84d387e4fa727f7587e1a0`\n- `Linux >= 9a0045088d888c9c539c8c626a366cb52c0fbdab < 557c024ca7250bb65ae60f16c02074106c2f197b`\n- `Linux 2.6.26`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}