{"id":"CVE-2026-53041","state":"PUBLISHED","title":"ocfs2: fix listxattr handling when the buffer is full","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix listxattr handling when the buffer is full\n\n[BUG]\nIf an OCFS2 inode has both inline and block-based xattrs, listxattr()\ncan return a size larger than the caller's buffer when the inline names\nconsume that buffer exactly.\n\nkernel BUG at mm/usercopy.c:102!\nOops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\nRIP: 0010:usercopy_abort+0xb7/0xd0 mm/usercopy.c:102\nCall Trace:\n __check_heap_object+0xe3/0x120 mm/slub.c:8243\n check_heap_object mm/usercopy.c:196 [inline]\n __check_object_size mm/usercopy.c:250 [inline]\n __check_object_size+0x5c5/0x780 mm/usercopy.c:215\n check_object_size include/linux/ucopysize.h:22 [inline]\n check_copy_size include/linux/ucopysize.h:59 [inline]\n copy_to_user include/linux/uaccess.h:219 [inline]\n listxattr+0xb0/0x170 fs/xattr.c:926\n filename_listxattr fs/xattr.c:958 [inline]\n path_listxattrat+0x137/0x320 fs/xattr.c:988\n __do_sys_listxattr fs/xattr.c:1001 [inline]\n __se_sys_listxattr fs/xattr.c:998 [inline]\n __x64_sys_listxattr+0x7f/0xd0 fs/xattr.c:998\n ...\n\n[CAUSE]\nCommit 936b8834366e (\"ocfs2: Refactor xattr list and remove\nocfs2_xattr_handler().\") replaced the old per-handler list accounting\nwith ocfs2_xattr_list_entry(), but it kept using size == 0 to detect\nprobe mode.\n\nThat assumption stops being true once ocfs2_listxattr() finishes the\ninline-xattr pass. If the inline names fill the caller buffer exactly,\nthe block-xattr pass runs with a non-NULL buffer and a remaining size of\nzero. ocfs2_xattr_list_entry() then skips the bounds check, keeps\ncounting block names, and returns a positive size larger than the\nsupplied buffer.\n\n[FIX]\nDetect probe mode by testing whether the destination buffer pointer is\nNULL instead of whether the remaining size is zero.\n\nThat restores the pre-refactor behavior and matches the OCFS2 getxattr\nhelpers. Once the remaining buffer reaches zero while more names are\nleft, the block-xattr pass now returns -ERANGE instead of reporting a\nsize larger than the allocated list buffer.","publishedAt":"2026-06-24T16:29:47.501Z","updatedAt":"2026-08-05T12:32:49.657Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"a35a1c2b170b5b578b1b3fecb95694796552af9a","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"2323084c17370304f49c84b354fe7b3edbb264fe","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"6f702b00b8124c5d3525f19172934544826a114d","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"d919b905939eda93393e3572900ff70dbad2b47f","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"46e66fefb83811958127bc9ad736983ec629d82b","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"2685df8577a38d83b367c8cf52eda9dc286959ff","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"50033ec1350fe68abdc63b950ced7ae57364b77a","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"d12f558e6200b3f47dbef9331ed6d115d2410e59","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.28","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.28","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/xattr.c"]}],"references":["https://git.kernel.org/stable/c/a35a1c2b170b5b578b1b3fecb95694796552af9a","https://git.kernel.org/stable/c/2323084c17370304f49c84b354fe7b3edbb264fe","https://git.kernel.org/stable/c/6f702b00b8124c5d3525f19172934544826a114d","https://git.kernel.org/stable/c/d919b905939eda93393e3572900ff70dbad2b47f","https://git.kernel.org/stable/c/46e66fefb83811958127bc9ad736983ec629d82b","https://git.kernel.org/stable/c/2685df8577a38d83b367c8cf52eda9dc286959ff","https://git.kernel.org/stable/c/50033ec1350fe68abdc63b950ced7ae57364b77a","https://git.kernel.org/stable/c/d12f558e6200b3f47dbef9331ed6d115d2410e59"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53041.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53041","state":"PUBLISHED","datePublished":"2026-06-24T16:29:47.501Z","dateUpdated":"2026-08-05T12:32:49.657Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.380Z"},"containers":{"cna":{"title":"ocfs2: fix listxattr handling when the buffer is full","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix listxattr handling when the buffer is full\n\n[BUG]\nIf an OCFS2 inode has both inline and block-based xattrs, listxattr()\ncan return a size larger than the caller's buffer when the inline names\nconsume that buffer exactly.\n\nkernel BUG at mm/usercopy.c:102!\nOops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\nRIP: 0010:usercopy_abort+0xb7/0xd0 mm/usercopy.c:102\nCall Trace:\n __check_heap_object+0xe3/0x120 mm/slub.c:8243\n check_heap_object mm/usercopy.c:196 [inline]\n __check_object_size mm/usercopy.c:250 [inline]\n __check_object_size+0x5c5/0x780 mm/usercopy.c:215\n check_object_size include/linux/ucopysize.h:22 [inline]\n check_copy_size include/linux/ucopysize.h:59 [inline]\n copy_to_user include/linux/uaccess.h:219 [inline]\n listxattr+0xb0/0x170 fs/xattr.c:926\n filename_listxattr fs/xattr.c:958 [inline]\n path_listxattrat+0x137/0x320 fs/xattr.c:988\n __do_sys_listxattr fs/xattr.c:1001 [inline]\n __se_sys_listxattr fs/xattr.c:998 [inline]\n __x64_sys_listxattr+0x7f/0xd0 fs/xattr.c:998\n ...\n\n[CAUSE]\nCommit 936b8834366e (\"ocfs2: Refactor xattr list and remove\nocfs2_xattr_handler().\") replaced the old per-handler list accounting\nwith ocfs2_xattr_list_entry(), but it kept using size == 0 to detect\nprobe mode.\n\nThat assumption stops being true once ocfs2_listxattr() finishes the\ninline-xattr pass. If the inline names fill the caller buffer exactly,\nthe block-xattr pass runs with a non-NULL buffer and a remaining size of\nzero. ocfs2_xattr_list_entry() then skips the bounds check, keeps\ncounting block names, and returns a positive size larger than the\nsupplied buffer.\n\n[FIX]\nDetect probe mode by testing whether the destination buffer pointer is\nNULL instead of whether the remaining size is zero.\n\nThat restores the pre-refactor behavior and matches the OCFS2 getxattr\nhelpers. Once the remaining buffer reaches zero while more names are\nleft, the block-xattr pass now returns -ERANGE instead of reporting a\nsize larger than the allocated list buffer."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"a35a1c2b170b5b578b1b3fecb95694796552af9a","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"2323084c17370304f49c84b354fe7b3edbb264fe","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"6f702b00b8124c5d3525f19172934544826a114d","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"d919b905939eda93393e3572900ff70dbad2b47f","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"46e66fefb83811958127bc9ad736983ec629d82b","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"2685df8577a38d83b367c8cf52eda9dc286959ff","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"50033ec1350fe68abdc63b950ced7ae57364b77a","versionType":"git"},{"version":"936b8834366ec05f2a6993f73afd8348cac9718e","status":"affected","lessThan":"d12f558e6200b3f47dbef9331ed6d115d2410e59","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.28","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.28","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/xattr.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/a35a1c2b170b5b578b1b3fecb95694796552af9a"},{"url":"https://git.kernel.org/stable/c/2323084c17370304f49c84b354fe7b3edbb264fe"},{"url":"https://git.kernel.org/stable/c/6f702b00b8124c5d3525f19172934544826a114d"},{"url":"https://git.kernel.org/stable/c/d919b905939eda93393e3572900ff70dbad2b47f"},{"url":"https://git.kernel.org/stable/c/46e66fefb83811958127bc9ad736983ec629d82b"},{"url":"https://git.kernel.org/stable/c/2685df8577a38d83b367c8cf52eda9dc286959ff"},{"url":"https://git.kernel.org/stable/c/50033ec1350fe68abdc63b950ced7ae57364b77a"},{"url":"https://git.kernel.org/stable/c/d12f558e6200b3f47dbef9331ed6d115d2410e59"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable OCFS2 code is reached through local `listxattr`/`llistxattr`/`flistxattr`/`listxattrat` syscalls where the caller controls the too-small buffer size. Network wrappers such as nfsd and ksmbd probe and allocate the full xattr-list size, so they do not expose the short-buffer trigger.\nAC:L - The attacker can deterministically create the needed inline-plus-block xattr layout on a writable OCFS2 file using `user.*` xattrs, then pass a buffer size that exactly fits the inline names. No race or external timing condition is required.\nPR:L - A basic local unprivileged user with access to a writable OCFS2 file or directory can create `user.*` xattrs and invoke `listxattr`. Creating/mounting the filesystem may require administrator setup, but exploitation on an affected deployed system does not require real root.\nUI:N - Once the attacker has local access to the OCFS2 path, exploitation is performed directly with syscalls. No separate victim action is needed.\nS:U - The issue affects kernel filesystem handling within the same host security authority. It is not a VM escape, IOMMU bypass, or other cross-scope boundary violation.\nC:H - The bug returns a length larger than the allocated kernel xattr-list buffer, causing `copy_to_user` to attempt an out-of-bounds kernel heap read. With hardened usercopy this aborts, but without it or under weaker checking this can expose kernel memory, so confidentiality is high.\nI:N - The flaw is an oversized read/copy length and does not write beyond bounds or corrupt kernel objects. It does not provide a direct integrity modification primitive.\nA:H - On hardened-usercopy kernels the overlong `copy_to_user` triggers `usercopy_abort()` and `BUG()`, producing a kernel oops/panic. The crash is repeatable by the local attacker."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:32:49.657Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.28","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.28","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.28","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.28","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.28","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.28","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.28","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.28","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}