CVE-2022-49068
"Btrfs Delalloc Release Extents Vulnerability"
Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: release correct delalloc amount in direct IO write path Running generic/406 causes the following WARNING in btrfs_destroy_inode() which tells there are outstanding extents left. In btrfs_get_blocks_direct_write(), we reserve a temporary outstanding extents with btrfs_delalloc_reserve_metadata() (or indirectly from btrfs_delalloc_reserve_space(()). We then release the outstanding extents with btrfs_delalloc_release_extents(). However, the "len" can be modified in the COW case, which releases fewer outstanding extents than expected. Fix it by calling btrfs_delalloc_release_extents() for the original length. To reproduce the warning, the filesystem should be 1 GiB. It's triggering a short-write, due to not being able to allocate a large extent and instead allocating a smaller one. WARNING: CPU: 0 PID: 757 at fs/btrfs/inode.c:8848 btrfs_destroy_inode+0x1e6/0x210 [btrfs] Modules linked in: btrfs blake2b_generic xor lzo_compress lzo_decompress raid6_pq zstd zstd_decompress zstd_compress xxhash zram zsmalloc CPU: 0 PID: 757 Comm: umount Not tainted 5.17.0-rc8+ #101 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014 RIP: 0010:btrfs_destroy_inode+0x1e6/0x210 [btrfs] RSP: 0018:ffffc9000327bda8 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff888100548b78 RCX: 0000000000000000 RDX: 0000000000026900 RSI: 0000000000000000 RDI: ffff888100548b78 RBP: ffff888100548940 R08: 0000000000000000 R09: ffff88810b48aba8 R10: 0000000000000001 R11: ffff8881004eb240 R12: ffff88810b48a800 R13: ffff88810b48ec08 R14: ffff88810b48ed00 R15: ffff888100490c68 FS: 00007f8549ea0b80(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f854a09e733 CR3: 000000010a2e9003 CR4: 0000000000370eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> destroy_inode+0x33/0x70 dispose_list+0x43/0x60 evict_inodes+0x161/0x1b0 generic_shutdown_super+0x2d/0x110 kill_anon_super+0xf/0x20 btrfs_kill_super+0xd/0x20 [btrfs] deactivate_locked_super+0x27/0x90 cleanup_mnt+0x12c/0x180 task_work_run+0x54/0x80 exit_to_user_mode_prepare+0x152/0x160 syscall_exit_to_user_mode+0x12/0x30 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f854a000fb7
INFO
Published Date :
Feb. 26, 2025, 7 a.m.
Last Modified :
Feb. 26, 2025, 7 a.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
Exploitability Score :
References to Advisories, Solutions, and Tools
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CVE-2022-49068.
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CVE-2022-49068 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Feb. 26, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: btrfs: release correct delalloc amount in direct IO write path Running generic/406 causes the following WARNING in btrfs_destroy_inode() which tells there are outstanding extents left. In btrfs_get_blocks_direct_write(), we reserve a temporary outstanding extents with btrfs_delalloc_reserve_metadata() (or indirectly from btrfs_delalloc_reserve_space(()). We then release the outstanding extents with btrfs_delalloc_release_extents(). However, the "len" can be modified in the COW case, which releases fewer outstanding extents than expected. Fix it by calling btrfs_delalloc_release_extents() for the original length. To reproduce the warning, the filesystem should be 1 GiB. It's triggering a short-write, due to not being able to allocate a large extent and instead allocating a smaller one. WARNING: CPU: 0 PID: 757 at fs/btrfs/inode.c:8848 btrfs_destroy_inode+0x1e6/0x210 [btrfs] Modules linked in: btrfs blake2b_generic xor lzo_compress lzo_decompress raid6_pq zstd zstd_decompress zstd_compress xxhash zram zsmalloc CPU: 0 PID: 757 Comm: umount Not tainted 5.17.0-rc8+ #101 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014 RIP: 0010:btrfs_destroy_inode+0x1e6/0x210 [btrfs] RSP: 0018:ffffc9000327bda8 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff888100548b78 RCX: 0000000000000000 RDX: 0000000000026900 RSI: 0000000000000000 RDI: ffff888100548b78 RBP: ffff888100548940 R08: 0000000000000000 R09: ffff88810b48aba8 R10: 0000000000000001 R11: ffff8881004eb240 R12: ffff88810b48a800 R13: ffff88810b48ec08 R14: ffff88810b48ed00 R15: ffff888100490c68 FS: 00007f8549ea0b80(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f854a09e733 CR3: 000000010a2e9003 CR4: 0000000000370eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> destroy_inode+0x33/0x70 dispose_list+0x43/0x60 evict_inodes+0x161/0x1b0 generic_shutdown_super+0x2d/0x110 kill_anon_super+0xf/0x20 btrfs_kill_super+0xd/0x20 [btrfs] deactivate_locked_super+0x27/0x90 cleanup_mnt+0x12c/0x180 task_work_run+0x54/0x80 exit_to_user_mode_prepare+0x152/0x160 syscall_exit_to_user_mode+0x12/0x30 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f854a000fb7 Added Reference https://git.kernel.org/stable/c/07cacfd9d9dc134557ac8866c73d570a59b3d1f3 Added Reference https://git.kernel.org/stable/c/6d82ad13c4110e73c7b0392f00534a1502a1b520 Added Reference https://git.kernel.org/stable/c/a04d37ddfe4be431b9e52e8504490376ab0a39a4
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2022-49068 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2022-49068
weaknesses.