// For flags

CVE-2022-49068

btrfs: release correct delalloc amount in direct IO write path

Time Line
Published
2024-03-19
Updated
2024-03-19
Firt exploit
2024-03-19
Overview
Descriptions (1)
MITRE
CWE (0)
CAPEC (-)
Risk
CVSS Score
-
SSVC
-
KEV
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EPSS
Affected Products (-)
Vendors (1)
linux
Products (1)
linux_kernel
Versions (4)
>= 5.15.27 < 5.15.35, >= 5.17 < 5.17.4, >= 5.17 < 5.18, 5.16.13
Intel Resources (-)
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References (6)
General (3)
kernel
Exploits & POcs (-)
Patches (3)
kernel
Advisories (-)
Summary
Descriptions

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

*Credits: N/A
CVSS Scores
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Privileges Required
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User Interaction
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Scope
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* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
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Automatable
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* Organization's Worst-case Scenario
Timeline
  • 2025-02-26 CVE Reserved
  • 2025-02-26 CVE Published
  • 2025-02-26 CVE Updated
  • ---------- EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Threat Intelligence Resources (0)
Security Advisory details:

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Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.15.27 < 5.15.35
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.15.27 < 5.15.35"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.17 < 5.17.4
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.17 < 5.17.4"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.17 < 5.18
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.17 < 5.18"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 5.16.13
Search vendor "Linux" for product "Linux Kernel" and version "5.16.13"
en
Affected