{"id":"CVE-2024-26616","state":"PUBLISHED","title":"btrfs: scrub: avoid use-after-free when chunk length is not 64K aligned","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: scrub: avoid use-after-free when chunk length is not 64K aligned\n\n[BUG]\nThere is a bug report that, on a ext4-converted btrfs, scrub leads to\nvarious problems, including:\n\n- \"unable to find chunk map\" errors\n  BTRFS info (device vdb): scrub: started on devid 1\n  BTRFS critical (device vdb): unable to find chunk map for logical 2214744064 length 4096\n  BTRFS critical (device vdb): unable to find chunk map for logical 2214744064 length 45056\n\n  This would lead to unrepariable errors.\n\n- Use-after-free KASAN reports:\n  ==================================================================\n  BUG: KASAN: slab-use-after-free in __blk_rq_map_sg+0x18f/0x7c0\n  Read of size 8 at addr ffff8881013c9040 by task btrfs/909\n  CPU: 0 PID: 909 Comm: btrfs Not tainted 6.7.0-x64v3-dbg #11 c50636e9419a8354555555245df535e380563b2b\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 2023.11-2 12/24/2023\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x43/0x60\n   print_report+0xcf/0x640\n   kasan_report+0xa6/0xd0\n   __blk_rq_map_sg+0x18f/0x7c0\n   virtblk_prep_rq.isra.0+0x215/0x6a0 [virtio_blk 19a65eeee9ae6fcf02edfad39bb9ddee07dcdaff]\n   virtio_queue_rqs+0xc4/0x310 [virtio_blk 19a65eeee9ae6fcf02edfad39bb9ddee07dcdaff]\n   blk_mq_flush_plug_list.part.0+0x780/0x860\n   __blk_flush_plug+0x1ba/0x220\n   blk_finish_plug+0x3b/0x60\n   submit_initial_group_read+0x10a/0x290 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   flush_scrub_stripes+0x38e/0x430 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   scrub_stripe+0x82a/0xae0 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   scrub_chunk+0x178/0x200 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   scrub_enumerate_chunks+0x4bc/0xa30 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   btrfs_scrub_dev+0x398/0x810 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   btrfs_ioctl+0x4b9/0x3020 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   __x64_sys_ioctl+0xbd/0x100\n   do_syscall_64+0x5d/0xe0\n   entry_SYSCALL_64_after_hwframe+0x63/0x6b\n  RIP: 0033:0x7f47e5e0952b\n\n- Crash, mostly due to above use-after-free\n\n[CAUSE]\nThe converted fs has the following data chunk layout:\n\n    item 2 key (FIRST_CHUNK_TREE CHUNK_ITEM 2214658048) itemoff 16025 itemsize 80\n        length 86016 owner 2 stripe_len 65536 type DATA|single\n\nFor above logical bytenr 2214744064, it's at the chunk end\n(2214658048 + 86016 = 2214744064).\n\nThis means btrfs_submit_bio() would split the bio, and trigger endio\nfunction for both of the two halves.\n\nHowever scrub_submit_initial_read() would only expect the endio function\nto be called once, not any more.\nThis means the first endio function would already free the bbio::bio,\nleaving the bvec freed, thus the 2nd endio call would lead to\nuse-after-free.\n\n[FIX]\n- Make sure scrub_read_endio() only updates bits in its range\n  Since we may read less than 64K at the end of the chunk, we should not\n  touch the bits beyond chunk boundary.\n\n- Make sure scrub_submit_initial_read() only to read the chunk range\n  This is done by calculating the real number of sectors we need to\n  read, and add sector-by-sector to the bio.\n\nThankfully the scrub read repair path won't need extra fixes:\n\n- scrub_stripe_submit_repair_read()\n  With above fixes, we won't update error bit for range beyond chunk,\n  thus scrub_stripe_submit_repair_read() should never submit any read\n  beyond the chunk.","publishedAt":"2024-02-29T15:52:19.452Z","updatedAt":"2026-05-11T20:00:50.930Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e02ee89baa66c40e1002cf8b09141fce7265e0f5","status":"affected","lessThan":"642b9c520ef2f104277ad1f902f8526edbe087fb","versionType":"git"},{"version":"e02ee89baa66c40e1002cf8b09141fce7265e0f5","status":"affected","lessThan":"34de0f04684ec00c093a0455648be055f0e8e24f","versionType":"git"},{"version":"e02ee89baa66c40e1002cf8b09141fce7265e0f5","status":"affected","lessThan":"f546c4282673497a06ecb6190b50ae7f6c85b02f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/scrub.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.4","versionType":"semver"},{"version":"6.6.15","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.7.3","status":"unaffected","lessThanOrEqual":"6.7.*","versionType":"semver"},{"version":"6.8","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/scrub.c"]}],"references":["https://git.kernel.org/stable/c/642b9c520ef2f104277ad1f902f8526edbe087fb","https://git.kernel.org/stable/c/34de0f04684ec00c093a0455648be055f0e8e24f","https://git.kernel.org/stable/c/f546c4282673497a06ecb6190b50ae7f6c85b02f"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:10.607Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/26xxx/CVE-2024-26616.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-26616","state":"PUBLISHED","datePublished":"2024-02-29T15:52:19.452Z","dateUpdated":"2026-05-11T20:00:50.930Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-02-19T14:20:24.131Z"},"containers":{"cna":{"title":"btrfs: scrub: avoid use-after-free when chunk length is not 64K aligned","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: scrub: avoid use-after-free when chunk length is not 64K aligned\n\n[BUG]\nThere is a bug report that, on a ext4-converted btrfs, scrub leads to\nvarious problems, including:\n\n- \"unable to find chunk map\" errors\n  BTRFS info (device vdb): scrub: started on devid 1\n  BTRFS critical (device vdb): unable to find chunk map for logical 2214744064 length 4096\n  BTRFS critical (device vdb): unable to find chunk map for logical 2214744064 length 45056\n\n  This would lead to unrepariable errors.\n\n- Use-after-free KASAN reports:\n  ==================================================================\n  BUG: KASAN: slab-use-after-free in __blk_rq_map_sg+0x18f/0x7c0\n  Read of size 8 at addr ffff8881013c9040 by task btrfs/909\n  CPU: 0 PID: 909 Comm: btrfs Not tainted 6.7.0-x64v3-dbg #11 c50636e9419a8354555555245df535e380563b2b\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 2023.11-2 12/24/2023\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x43/0x60\n   print_report+0xcf/0x640\n   kasan_report+0xa6/0xd0\n   __blk_rq_map_sg+0x18f/0x7c0\n   virtblk_prep_rq.isra.0+0x215/0x6a0 [virtio_blk 19a65eeee9ae6fcf02edfad39bb9ddee07dcdaff]\n   virtio_queue_rqs+0xc4/0x310 [virtio_blk 19a65eeee9ae6fcf02edfad39bb9ddee07dcdaff]\n   blk_mq_flush_plug_list.part.0+0x780/0x860\n   __blk_flush_plug+0x1ba/0x220\n   blk_finish_plug+0x3b/0x60\n   submit_initial_group_read+0x10a/0x290 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   flush_scrub_stripes+0x38e/0x430 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   scrub_stripe+0x82a/0xae0 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   scrub_chunk+0x178/0x200 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   scrub_enumerate_chunks+0x4bc/0xa30 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   btrfs_scrub_dev+0x398/0x810 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   btrfs_ioctl+0x4b9/0x3020 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]\n   __x64_sys_ioctl+0xbd/0x100\n   do_syscall_64+0x5d/0xe0\n   entry_SYSCALL_64_after_hwframe+0x63/0x6b\n  RIP: 0033:0x7f47e5e0952b\n\n- Crash, mostly due to above use-after-free\n\n[CAUSE]\nThe converted fs has the following data chunk layout:\n\n    item 2 key (FIRST_CHUNK_TREE CHUNK_ITEM 2214658048) itemoff 16025 itemsize 80\n        length 86016 owner 2 stripe_len 65536 type DATA|single\n\nFor above logical bytenr 2214744064, it's at the chunk end\n(2214658048 + 86016 = 2214744064).\n\nThis means btrfs_submit_bio() would split the bio, and trigger endio\nfunction for both of the two halves.\n\nHowever scrub_submit_initial_read() would only expect the endio function\nto be called once, not any more.\nThis means the first endio function would already free the bbio::bio,\nleaving the bvec freed, thus the 2nd endio call would lead to\nuse-after-free.\n\n[FIX]\n- Make sure scrub_read_endio() only updates bits in its range\n  Since we may read less than 64K at the end of the chunk, we should not\n  touch the bits beyond chunk boundary.\n\n- Make sure scrub_submit_initial_read() only to read the chunk range\n  This is done by calculating the real number of sectors we need to\n  read, and add sector-by-sector to the bio.\n\nThankfully the scrub read repair path won't need extra fixes:\n\n- scrub_stripe_submit_repair_read()\n  With above fixes, we won't update error bit for range beyond chunk,\n  thus scrub_stripe_submit_repair_read() should never submit any read\n  beyond the chunk."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e02ee89baa66c40e1002cf8b09141fce7265e0f5","status":"affected","lessThan":"642b9c520ef2f104277ad1f902f8526edbe087fb","versionType":"git"},{"version":"e02ee89baa66c40e1002cf8b09141fce7265e0f5","status":"affected","lessThan":"34de0f04684ec00c093a0455648be055f0e8e24f","versionType":"git"},{"version":"e02ee89baa66c40e1002cf8b09141fce7265e0f5","status":"affected","lessThan":"f546c4282673497a06ecb6190b50ae7f6c85b02f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/scrub.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.4","versionType":"semver"},{"version":"6.6.15","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.7.3","status":"unaffected","lessThanOrEqual":"6.7.*","versionType":"semver"},{"version":"6.8","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/scrub.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/642b9c520ef2f104277ad1f902f8526edbe087fb"},{"url":"https://git.kernel.org/stable/c/34de0f04684ec00c093a0455648be055f0e8e24f"},{"url":"https://git.kernel.org/stable/c/f546c4282673497a06ecb6190b50ae7f6c85b02f"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T20:00:50.930Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.4","versionEndExcluding":"6.6.15"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.4","versionEndExcluding":"6.7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.4","versionEndExcluding":"6.8"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/642b9c520ef2f104277ad1f902f8526edbe087fb","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/34de0f04684ec00c093a0455648be055f0e8e24f","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/f546c4282673497a06ecb6190b50ae7f6c85b02f","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-02T00:07:19.788Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-26616","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T15:57:14.247460Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-11T17:33:49.394Z"}}]}}}