{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38358", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.007Z", "datePublished": "2025-07-25T12:47:29.515Z", "dateUpdated": "2026-05-11T21:26:26.720Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T21:26:26.720Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix race between async reclaim worker and close_ctree()\n\nSyzbot reported an assertion failure due to an attempt to add a delayed\niput after we have set BTRFS_FS_STATE_NO_DELAYED_IPUT in the fs_info\nstate:\n\n WARNING: CPU: 0 PID: 65 at fs/btrfs/inode.c:3420 btrfs_add_delayed_iput+0x2f8/0x370 fs/btrfs/inode.c:3420\n Modules linked in:\n CPU: 0 UID: 0 PID: 65 Comm: kworker/u8:4 Not tainted 6.15.0-next-20250530-syzkaller #0 PREEMPT(full)\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025\n Workqueue: btrfs-endio-write btrfs_work_helper\n RIP: 0010:btrfs_add_delayed_iput+0x2f8/0x370 fs/btrfs/inode.c:3420\n Code: 4e ad 5d (...)\n RSP: 0018:ffffc9000213f780 EFLAGS: 00010293\n RAX: ffffffff83c635b7 RBX: ffff888058920000 RCX: ffff88801c769e00\n RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000000000000000\n RBP: 0000000000000001 R08: ffff888058921b67 R09: 1ffff1100b12436c\n R10: dffffc0000000000 R11: ffffed100b12436d R12: 0000000000000001\n R13: dffffc0000000000 R14: ffff88807d748000 R15: 0000000000000100\n FS: 0000000000000000(0000) GS:ffff888125c53000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00002000000bd038 CR3: 000000006a142000 CR4: 00000000003526f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n \n btrfs_put_ordered_extent+0x19f/0x470 fs/btrfs/ordered-data.c:635\n btrfs_finish_one_ordered+0x11d8/0x1b10 fs/btrfs/inode.c:3312\n btrfs_work_helper+0x399/0xc20 fs/btrfs/async-thread.c:312\n process_one_work kernel/workqueue.c:3238 [inline]\n process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321\n worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402\n kthread+0x70e/0x8a0 kernel/kthread.c:464\n ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n \n\nThis can happen due to a race with the async reclaim worker like this:\n\n1) The async metadata reclaim worker enters shrink_delalloc(), which calls\n btrfs_start_delalloc_roots() with an nr_pages argument that has a value\n less than LONG_MAX, and that in turn enters start_delalloc_inodes(),\n which sets the local variable 'full_flush' to false because\n wbc->nr_to_write is less than LONG_MAX;\n\n2) There it finds inode X in a root's delalloc list, grabs a reference for\n inode X (with igrab()), and triggers writeback for it with\n filemap_fdatawrite_wbc(), which creates an ordered extent for inode X;\n\n3) The unmount sequence starts from another task, we enter close_ctree()\n and we flush the workqueue fs_info->endio_write_workers, which waits\n for the ordered extent for inode X to complete and when dropping the\n last reference of the ordered extent, with btrfs_put_ordered_extent(),\n when we call btrfs_add_delayed_iput() we don't add the inode to the\n list of delayed iputs because it has a refcount of 2, so we decrement\n it to 1 and return;\n\n4) Shortly after at close_ctree() we call btrfs_run_delayed_iputs() which\n runs all delayed iputs, and then we set BTRFS_FS_STATE_NO_DELAYED_IPUT\n in the fs_info state;\n\n5) The async reclaim worker, after calling filemap_fdatawrite_wbc(), now\n calls btrfs_add_delayed_iput() for inode X and there we trigger an\n assertion failure since the fs_info state has the flag\n BTRFS_FS_STATE_NO_DELAYED_IPUT set.\n\nFix this by setting BTRFS_FS_STATE_NO_DELAYED_IPUT only after we wait for\nthe async reclaim workers to finish, after we call cancel_work_sync() for\nthem at close_ctree(), and by running delayed iputs after wait for the\nreclaim workers to finish and before setting the bit.\n\nThis race was recently introduced by commit 19e60b2a95f5 (\"btrfs: add\nextra warning if delayed iput is added when it's not allowed\"). Without\nthe new validation at btrfs_add_delayed_iput(), \n---truncated---" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/btrfs/disk-io.c" ], "versions": [ { "version": "19e60b2a95f5d6b77d972c7bec35a11e70fd118c", "lessThan": "4693cda2c06039c875f2eef0123b22340c34bfa0", "status": "affected", "versionType": "git" }, { "version": "19e60b2a95f5d6b77d972c7bec35a11e70fd118c", "lessThan": "a26bf338cdad3643a6e7c3d78a172baadba15c1a", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/btrfs/disk-io.c" ], "versions": [ { "version": "6.15", "status": "affected" }, { "version": "0", "lessThan": "6.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.5", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "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": "6.15", "versionEndExcluding": "6.15.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4693cda2c06039c875f2eef0123b22340c34bfa0" }, { "url": "https://git.kernel.org/stable/c/a26bf338cdad3643a6e7c3d78a172baadba15c1a" } ], "title": "btrfs: fix race between async reclaim worker and close_ctree()", "x_generator": { "engine": "bippy-1.2.0" } } } }