ghsa-x5vm-26pp-xff5
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
btrfs: lock the inode in shared mode before starting fiemap
Currently fiemap does not take the inode's lock (VFS lock), it only locks a file range in the inode's io tree. This however can lead to a deadlock if we have a concurrent fsync on the file and fiemap code triggers a fault when accessing the user space buffer with fiemap_fill_next_extent(). The deadlock happens on the inode's i_mmap_lock semaphore, which is taken both by fsync and btrfs_page_mkwrite(). This deadlock was recently reported by syzbot and triggers a trace like the following:
task:syz-executor361 state:D stack:20264 pid:5668 ppid:5119 flags:0x00004004
Call Trace:
{
"affected": [],
"aliases": [
"CVE-2023-52737"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-21T16:15:13Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: lock the inode in shared mode before starting fiemap\n\nCurrently fiemap does not take the inode\u0027s lock (VFS lock), it only locks\na file range in the inode\u0027s io tree. This however can lead to a deadlock\nif we have a concurrent fsync on the file and fiemap code triggers a fault\nwhen accessing the user space buffer with fiemap_fill_next_extent(). The\ndeadlock happens on the inode\u0027s i_mmap_lock semaphore, which is taken both\nby fsync and btrfs_page_mkwrite(). This deadlock was recently reported by\nsyzbot and triggers a trace like the following:\n\n task:syz-executor361 state:D stack:20264 pid:5668 ppid:5119 flags:0x00004004\n Call Trace:\n \u003cTASK\u003e\n context_switch kernel/sched/core.c:5293 [inline]\n __schedule+0x995/0xe20 kernel/sched/core.c:6606\n schedule+0xcb/0x190 kernel/sched/core.c:6682\n wait_on_state fs/btrfs/extent-io-tree.c:707 [inline]\n wait_extent_bit+0x577/0x6f0 fs/btrfs/extent-io-tree.c:751\n lock_extent+0x1c2/0x280 fs/btrfs/extent-io-tree.c:1742\n find_lock_delalloc_range+0x4e6/0x9c0 fs/btrfs/extent_io.c:488\n writepage_delalloc+0x1ef/0x540 fs/btrfs/extent_io.c:1863\n __extent_writepage+0x736/0x14e0 fs/btrfs/extent_io.c:2174\n extent_write_cache_pages+0x983/0x1220 fs/btrfs/extent_io.c:3091\n extent_writepages+0x219/0x540 fs/btrfs/extent_io.c:3211\n do_writepages+0x3c3/0x680 mm/page-writeback.c:2581\n filemap_fdatawrite_wbc+0x11e/0x170 mm/filemap.c:388\n __filemap_fdatawrite_range mm/filemap.c:421 [inline]\n filemap_fdatawrite_range+0x175/0x200 mm/filemap.c:439\n btrfs_fdatawrite_range fs/btrfs/file.c:3850 [inline]\n start_ordered_ops fs/btrfs/file.c:1737 [inline]\n btrfs_sync_file+0x4ff/0x1190 fs/btrfs/file.c:1839\n generic_write_sync include/linux/fs.h:2885 [inline]\n btrfs_do_write_iter+0xcd3/0x1280 fs/btrfs/file.c:1684\n call_write_iter include/linux/fs.h:2189 [inline]\n new_sync_write fs/read_write.c:491 [inline]\n vfs_write+0x7dc/0xc50 fs/read_write.c:584\n ksys_write+0x177/0x2a0 fs/read_write.c:637\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n RIP: 0033:0x7f7d4054e9b9\n RSP: 002b:00007f7d404fa2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001\n RAX: ffffffffffffffda RBX: 00007f7d405d87a0 RCX: 00007f7d4054e9b9\n RDX: 0000000000000090 RSI: 0000000020000000 RDI: 0000000000000006\n RBP: 00007f7d405a51d0 R08: 0000000000000000 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000246 R12: 61635f65646f6e69\n R13: 65646f7475616f6e R14: 7261637369646f6e R15: 00007f7d405d87a8\n \u003c/TASK\u003e\n INFO: task syz-executor361:5697 blocked for more than 145 seconds.\n Not tainted 6.2.0-rc3-syzkaller-00376-g7c6984405241 #0\n \"echo 0 \u003e /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\n task:syz-executor361 state:D stack:21216 pid:5697 ppid:5119 flags:0x00004004\n Call Trace:\n \u003cTASK\u003e\n context_switch kernel/sched/core.c:5293 [inline]\n __schedule+0x995/0xe20 kernel/sched/core.c:6606\n schedule+0xcb/0x190 kernel/sched/core.c:6682\n rwsem_down_read_slowpath+0x5f9/0x930 kernel/locking/rwsem.c:1095\n __down_read_common+0x54/0x2a0 kernel/locking/rwsem.c:1260\n btrfs_page_mkwrite+0x417/0xc80 fs/btrfs/inode.c:8526\n do_page_mkwrite+0x19e/0x5e0 mm/memory.c:2947\n wp_page_shared+0x15e/0x380 mm/memory.c:3295\n handle_pte_fault mm/memory.c:4949 [inline]\n __handle_mm_fault mm/memory.c:5073 [inline]\n handle_mm_fault+0x1b79/0x26b0 mm/memory.c:5219\n do_user_addr_fault+0x69b/0xcb0 arch/x86/mm/fault.c:1428\n handle_page_fault arch/x86/mm/fault.c:1519 [inline]\n exc_page_fault+0x7a/0x110 arch/x86/mm/fault.c:1575\n asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570\n RIP: 0010:copy_user_short_string+0xd/0x40 arch/x86/lib/copy_user_64.S:233\n Code: 74 0a 89 (...)\n RSP: 0018:ffffc9000570f330 EFLAGS: 000502\n---truncated---",
"id": "GHSA-x5vm-26pp-xff5",
"modified": "2024-05-21T18:31:19Z",
"published": "2024-05-21T18:31:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-52737"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/519b7e13b5ae8dd38da1e52275705343be6bb508"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d8c594da79bc0244e610a70594e824a401802be1"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.