{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53698","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-10-22T13:21:37.345Z","datePublished":"2025-10-22T13:23:38.384Z","dateUpdated":"2026-08-05T09:15:36.147Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T09:15:36.147Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxsk: fix refcount underflow in error path\n\nFix a refcount underflow problem reported by syzbot that can happen\nwhen a system is running out of memory. If xp_alloc_tx_descs() fails,\nand it can only fail due to not having enough memory, then the error\npath is triggered. In this error path, the refcount of the pool is\ndecremented as it has incremented before. However, the reference to\nthe pool in the socket was not nulled. This means that when the socket\nis closed later, the socket teardown logic will think that there is a\npool attached to the socket and try to decrease the refcount again,\nleading to a refcount underflow.\n\nI chose this fix as it involved adding just a single line. Another\noption would have been to move xp_get_pool() and the assignment of\nxs->pool to after the if-statement and using xs_umem->pool instead of\nxs->pool in the whole if-statement resulting in somewhat simpler code,\nbut this would have led to much more churn in the code base perhaps\nmaking it harder to backport."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerability is reached through the AF_XDP `socket()`/`setsockopt()`/`bind()` syscall interface, a purely local kernel API with no network exposure.\nAC:L - The attacker controls both sockets and the Tx-ring allocation size, and can induce memory pressure and recreate the pool to retry, making the required allocation failure inducible and repeatable.\nPR:L - Creating the AF_XDP socket requires CAP_NET_RAW, but this is checked against `net->user_ns`, so an unprivileged local user obtains it via an unprivileged user+network namespace (`unshare -Urn`).\nUI:N - The attacker performs all socket setup, binding, and teardown steps itself; no action by another user is required.\nS:U - The corruption is confined to the kernel's own buffer-pool objects within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The premature free produces a use-after-free of the `xsk_buff_pool`; a reclaimed-and-sprayed allocation lets the attacker read freed-object contents, yielding arbitrary kernel memory disclosure.\nI:H - The use-after-free/double-free of the pool provides a write primitive (dangling refcount and pool fields) exploitable via heap spraying for kernel memory corruption and control-flow hijacking.\nA:H - The refcount underflow frees a pool still in use by another socket, reliably causing use-after-free memory corruption, oops, or panic."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xdp/xsk.c"],"versions":[{"version":"f7019562f142bc041f9cde63af338d1886585923","lessThan":"789fcd94c9cac133dd4d96e193188661aca9f6c3","status":"affected","versionType":"git"},{"version":"ba3beec2ec1d3b4fd8672ca6e781dac4b3267f6e","lessThan":"15b453cf7348973217558235b9ece2ee5fea6777","status":"affected","versionType":"git"},{"version":"ba3beec2ec1d3b4fd8672ca6e781dac4b3267f6e","lessThan":"3e7722c31d4167eb7f3ffd35aba52cab69b79072","status":"affected","versionType":"git"},{"version":"ba3beec2ec1d3b4fd8672ca6e781dac4b3267f6e","lessThan":"85c2c79a07302fe68a1ad5cc449458cc559e314d","status":"affected","versionType":"git"},{"version":"9f0c8a9d4ef1b9ebee0e4ac2495fe790727044aa","status":"affected","versionType":"git"},{"version":"5.15.47","lessThan":"5.15.127","status":"affected","versionType":"semver"},{"version":"5.17.15","lessThan":"5.18","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xdp/xsk.c"],"versions":[{"version":"5.18","status":"affected"},{"version":"0","lessThan":"5.18","status":"unaffected","versionType":"semver"},{"version":"5.15.127","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.46","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.4.11","lessThanOrEqual":"6.4.*","status":"unaffected","versionType":"semver"},{"version":"6.5","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.47","versionEndExcluding":"5.15.127"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.1.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.4.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17.15"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/789fcd94c9cac133dd4d96e193188661aca9f6c3"},{"url":"https://git.kernel.org/stable/c/15b453cf7348973217558235b9ece2ee5fea6777"},{"url":"https://git.kernel.org/stable/c/3e7722c31d4167eb7f3ffd35aba52cab69b79072"},{"url":"https://git.kernel.org/stable/c/85c2c79a07302fe68a1ad5cc449458cc559e314d"}],"title":"xsk: fix refcount underflow in error path","x_generator":{"engine":"bippy-1.2.0"}}}}