{"cve":"CVE-2022-49007","nvd":{"published":"2024-10-21T20:15:12.197","modified":"2026-06-17T05:16:50.103","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix NULL pointer dereference in nilfs_palloc_commit_free_entry()\n\nSyzbot reported a null-ptr-deref bug:\n\n NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP\n frequency < 30 seconds\n general protection fault, probably for non-canonical address\n 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN\n KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]\n CPU: 1 PID: 3603 Comm: segctord Not tainted\n 6.1.0-rc2-syzkaller-00105-gb229b6ca5abb #0\n Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google\n 10/11/2022\n RIP: 0010:nilfs_palloc_commit_free_entry+0xe5/0x6b0\n fs/nilfs2/alloc.c:608\n Code: 00 00 00 00 fc ff df 80 3c 02 00 0f 85 cd 05 00 00 48 b8 00 00 00\n 00 00 fc ff df 4c 8b 73 08 49 8d 7e 10 48 89 fa 48 c1 ea 03 <80> 3c 02\n 00 0f 85 26 05 00 00 49 8b 46 10 be a6 00 00 00 48 c7 c7\n RSP: 0018:ffffc90003dff830 EFLAGS: 00010212\n RAX: dffffc0000000000 RBX: ffff88802594e218 RCX: 000000000000000d\n RDX: 0000000000000002 RSI: 0000000000002000 RDI: 0000000000000010\n RBP: ffff888071880222 R08: 0000000000000005 R09: 000000000000003f\n R10: 000000000000000d R11: 0000000000000000 R12: ffff888071880158\n R13: ffff88802594e220 R14: 0000000000000000 R15: 0000000000000004\n FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000)\n knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007fb1c08316a8 CR3: 0000000018560000 CR4: 0000000000350ee0\n Call Trace:\n  <TASK>\n  nilfs_dat_commit_free fs/nilfs2/dat.c:114 [inline]\n  nilfs_dat_commit_end+0x464/0x5f0 fs/nilfs2/dat.c:193\n  nilfs_dat_commit_update+0x26/0x40 fs/nilfs2/dat.c:236\n  nilfs_btree_commit_update_v+0x87/0x4a0 fs/nilfs2/btree.c:1940\n  nilfs_btree_commit_propagate_v fs/nilfs2/btree.c:2016 [inline]\n  nilfs_btree_propagate_v fs/nilfs2/btree.c:2046 [inline]\n  nilfs_btree_propagate+0xa00/0xd60 fs/nilfs2/btree.c:2088\n  nilfs_bmap_propagate+0x73/0x170 fs/nilfs2/bmap.c:337\n  nilfs_collect_file_data+0x45/0xd0 fs/nilfs2/segment.c:568\n  nilfs_segctor_apply_buffers+0x14a/0x470 fs/nilfs2/segment.c:1018\n  nilfs_segctor_scan_file+0x3f4/0x6f0 fs/nilfs2/segment.c:1067\n  nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1197 [inline]\n  nilfs_segctor_collect fs/nilfs2/segment.c:1503 [inline]\n  nilfs_segctor_do_construct+0x12fc/0x6af0 fs/nilfs2/segment.c:2045\n  nilfs_segctor_construct+0x8e3/0xb30 fs/nilfs2/segment.c:2379\n  nilfs_segctor_thread_construct fs/nilfs2/segment.c:2487 [inline]\n  nilfs_segctor_thread+0x3c3/0xf30 fs/nilfs2/segment.c:2570\n  kthread+0x2e4/0x3a0 kernel/kthread.c:376\n  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306\n  </TASK>\n ...\n\nIf DAT metadata file is corrupted on disk, there is a case where\nreq->pr_desc_bh is NULL and blocknr is 0 at nilfs_dat_commit_end() during\na b-tree operation that cascadingly updates ancestor nodes of the b-tree,\nbecause nilfs_dat_commit_alloc() for a lower level block can initialize\nthe blocknr on the same DAT entry between nilfs_dat_prepare_end() and\nnilfs_dat_commit_end().\n\nIf this happens, nilfs_dat_commit_end() calls nilfs_dat_commit_free()\nwithout valid buffer heads in req->pr_desc_bh and req->pr_bitmap_bh, and\ncauses the NULL pointer dereference above in\nnilfs_palloc_commit_free_entry() function, which leads to a crash.\n\nFix this by adding a NULL check on req->pr_desc_bh and req->pr_bitmap_bh\nbefore nilfs_palloc_commit_free_entry() in nilfs_dat_commit_free().\n\nThis also calls nilfs_error() in that case to notify that there is a fatal\nflaw in the filesystem metadata and prevent further operations.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/165c7a3b27a3857ebf57f626b9f38b48b6792e68","https://git.kernel.org/stable/c/2f2c59506ae39496588ceb8b88bdbdbaed895d63","https://git.kernel.org/stable/c/33021419fd81efd3d729a7f19341ba4b98fe66ce","https://git.kernel.org/stable/c/381b84f60e549ea98cec4666c6c728b1b3318756","https://git.kernel.org/stable/c/9a130b72e6bd1fb07fc3cde839dc6fb53da76f07"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:56:33.105311382+00:00"},"epss":{"cve":"CVE-2022-49007","score":0.00249,"percentile":0.16243,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}