{"id":"CVE-2022-49743","state":"PUBLISHED","title":"ovl: Use \"buf\" flexible array for memcpy() destination","description":"In the Linux kernel, the following vulnerability has been resolved:\n\novl: Use \"buf\" flexible array for memcpy() destination\n\nThe \"buf\" flexible array needs to be the memcpy() destination to avoid\nfalse positive run-time warning from the recent FORTIFY_SOURCE\nhardening:\n\n  memcpy: detected field-spanning write (size 93) of single field \"&fh->fb\"\n  at fs/overlayfs/export.c:799 (size 21)","publishedAt":"2025-03-27T16:42:54.289Z","updatedAt":"2026-10-15T21:21:07.990Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cbe7fba8edfc8cb8e621599e376f8ac5c224fa72","status":"affected","lessThan":"012cdef22000f3104e4fa8224ad29fde509b8caf","versionType":"git"},{"version":"cbe7fba8edfc8cb8e621599e376f8ac5c224fa72","status":"affected","lessThan":"a77141a06367825d639ac51b04703d551163e36c","versionType":"git"},{"version":"cbe7fba8edfc8cb8e621599e376f8ac5c224fa72","status":"affected","lessThan":"07a96977b2f462337a9121302de64277b8747ab1","versionType":"git"},{"version":"cbe7fba8edfc8cb8e621599e376f8ac5c224fa72","status":"affected","lessThan":"cf8aa9bf97cadf85745506c6a3e244b22c268d63","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/overlayfs/export.c","fs/overlayfs/overlayfs.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.248","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.93","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.11","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/overlayfs/export.c","fs/overlayfs/overlayfs.h"]}],"references":["https://git.kernel.org/stable/c/012cdef22000f3104e4fa8224ad29fde509b8caf","https://git.kernel.org/stable/c/a77141a06367825d639ac51b04703d551163e36c","https://git.kernel.org/stable/c/07a96977b2f462337a9121302de64277b8747ab1","https://git.kernel.org/stable/c/cf8aa9bf97cadf85745506c6a3e244b22c268d63"],"weaknesses":[],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/49xxx/CVE-2022-49743.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49743","state":"PUBLISHED","datePublished":"2025-03-27T16:42:54.289Z","dateUpdated":"2026-10-15T21:21:07.990Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-03-27T16:39:17.987Z"},"containers":{"cna":{"title":"ovl: Use \"buf\" flexible array for memcpy() destination","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\novl: Use \"buf\" flexible array for memcpy() destination\n\nThe \"buf\" flexible array needs to be the memcpy() destination to avoid\nfalse positive run-time warning from the recent FORTIFY_SOURCE\nhardening:\n\n  memcpy: detected field-spanning write (size 93) of single field \"&fh->fb\"\n  at fs/overlayfs/export.c:799 (size 21)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cbe7fba8edfc8cb8e621599e376f8ac5c224fa72","status":"affected","lessThan":"012cdef22000f3104e4fa8224ad29fde509b8caf","versionType":"git"},{"version":"cbe7fba8edfc8cb8e621599e376f8ac5c224fa72","status":"affected","lessThan":"a77141a06367825d639ac51b04703d551163e36c","versionType":"git"},{"version":"cbe7fba8edfc8cb8e621599e376f8ac5c224fa72","status":"affected","lessThan":"07a96977b2f462337a9121302de64277b8747ab1","versionType":"git"},{"version":"cbe7fba8edfc8cb8e621599e376f8ac5c224fa72","status":"affected","lessThan":"cf8aa9bf97cadf85745506c6a3e244b22c268d63","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/overlayfs/export.c","fs/overlayfs/overlayfs.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.248","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.93","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.11","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/overlayfs/export.c","fs/overlayfs/overlayfs.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/012cdef22000f3104e4fa8224ad29fde509b8caf"},{"url":"https://git.kernel.org/stable/c/a77141a06367825d639ac51b04703d551163e36c"},{"url":"https://git.kernel.org/stable/c/07a96977b2f462337a9121302de64277b8747ab1"},{"url":"https://git.kernel.org/stable/c/cf8aa9bf97cadf85745506c6a3e244b22c268d63"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - ovl_fid_to_fh() is reached via ovl_fh_to_dentry export_operations when an overlay is mounted with nfs_export=on and exported through nfsd; a remote NFS client triggers decode by sending a crafted OVL_FILEID_V0 (0xfb) filehandle.\nAC:L - The attacker fully controls the filehandle type and payload and can reliably force the V0 realignment memcpy path; no race or unpredictable victim state is required.\nPR:N - nfsd invokes exportfs_decode_fh during fh_verify before file permission checks; on common AUTH_SYS exports, any host permitted by the export list can send the crafted handle with no credentials.\nUI:N - Exploitation requires only sending an NFS request with a crafted filehandle; no victim user action is needed once the overlay is NFS-exported.\nS:U - Impact remains within the host kernel authority; this is not a VM escape, IOMMU bypass, or other cross-boundary breakout.\nC:N - The commit documents a FORTIFY_SOURCE false positive: kzalloc(buflen) correctly covers the memcpy of buflen-OVL_FH_WIRE_OFFSET, so there is no out-of-bounds read or information disclosure.\nI:N - There is no real buffer overflow or memory corruption—only a mis-typed memcpy destination (&fh->fb vs fh->buf)—so no write primitive or integrity impact exists.\nA:H - CONFIG_FORTIFY_SOURCE emits a kernel WARN_ONCE on the field-spanning write; with panic_on_warn (common on Android/hardened hosts) this becomes a kernel panic, matching DoS/crash severity."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:56:12.285Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.248"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.15.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.1.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2022-49743","role":"CISA 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