In the Linux kernel, the following vulnerability has been resolved:
btrfs: tree-checker: validate INODE_REF's namelen
[BUG]
A crafted btrfs image can trigger the following crash:
BUG: unable to handle page fault for address: ffffd1dc42884000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
CPU: 9 UID: 0 PID: 1034 Comm: poc Not tainted 7.1.0-rc4-custom+ #383 PREEMPT(full) 46af0a92938a63be7132e0dfd71e62327c51d5c2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
RIP: 0010:memcpy+0xc/0x10
Call Trace:
<TASK>
read_extent_buffer+0xe4/0x100 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f]
btrfs_get_name+0x15e/0x1e0 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f]
reconnect_path+0x165/0x390
exportfs_decode_fh_raw+0x337/0x400
? drop_caches_sysctl_handler+0xb0/0xb0
</TASK>
---[ end trace 0000000000000000 ]---
RIP: 0010:memcpy+0xc/0x10
Kernel panic - not syncing: Fatal exception
[CAUSE]
TThe crafted image has the following corrupted INODE_REF item:
item 9 key (258 INODE_REF 257) itemoff 11544 itemsize 4106
index 2 namelen 4096 name: d\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000
The itemsize matches the namelen, but the namelen is 4096, way larger
than normal name length limit (BTRFS_NAME_LEN, 255).
Meanwhile the memory of the @name is only 255 byte sized, this will cause
out-of-boundary access, and cause the above crash.
[FIX]
Add extra namelen verification for INODE_REF, just like what we have
done in ROOT_REF checks.
Now the crafted image can be rejected gracefully:
BTRFS critical (device dm-2): corrupt leaf: root=5 block=30572544 slot=14 ino=259, invalid inode ref name length, has 4096 expect [1, 255]
BTRFS error (device dm-2): read time tree block corruption detected on logical 30572544 mirror 2
[ Rebase, add a Link: tag, add an simple cause analyze ]
btrfs: tree-checker: validate INODE_REF's namelen
[BUG]
A crafted btrfs image can trigger the following crash:
BUG: unable to handle page fault for address: ffffd1dc42884000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
CPU: 9 UID: 0 PID: 1034 Comm: poc Not tainted 7.1.0-rc4-custom+ #383 PREEMPT(full) 46af0a92938a63be7132e0dfd71e62327c51d5c2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
RIP: 0010:memcpy+0xc/0x10
Call Trace:
<TASK>
read_extent_buffer+0xe4/0x100 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f]
btrfs_get_name+0x15e/0x1e0 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f]
reconnect_path+0x165/0x390
exportfs_decode_fh_raw+0x337/0x400
? drop_caches_sysctl_handler+0xb0/0xb0
</TASK>
---[ end trace 0000000000000000 ]---
RIP: 0010:memcpy+0xc/0x10
Kernel panic - not syncing: Fatal exception
[CAUSE]
TThe crafted image has the following corrupted INODE_REF item:
item 9 key (258 INODE_REF 257) itemoff 11544 itemsize 4106
index 2 namelen 4096 name: d\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000
The itemsize matches the namelen, but the namelen is 4096, way larger
than normal name length limit (BTRFS_NAME_LEN, 255).
Meanwhile the memory of the @name is only 255 byte sized, this will cause
out-of-boundary access, and cause the above crash.
[FIX]
Add extra namelen verification for INODE_REF, just like what we have
done in ROOT_REF checks.
Now the crafted image can be rejected gracefully:
BTRFS critical (device dm-2): corrupt leaf: root=5 block=30572544 slot=14 ino=259, invalid inode ref name length, has 4096 expect [1, 255]
BTRFS error (device dm-2): read time tree block corruption detected on logical 30572544 mirror 2
[ Rebase, add a Link: tag, add an simple cause analyze ]
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 24 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: btrfs: tree-checker: validate INODE_REF's namelen [BUG] A crafted btrfs image can trigger the following crash: BUG: unable to handle page fault for address: ffffd1dc42884000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page CPU: 9 UID: 0 PID: 1034 Comm: poc Not tainted 7.1.0-rc4-custom+ #383 PREEMPT(full) 46af0a92938a63be7132e0dfd71e62327c51d5c2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:memcpy+0xc/0x10 Call Trace: <TASK> read_extent_buffer+0xe4/0x100 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f] btrfs_get_name+0x15e/0x1e0 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f] reconnect_path+0x165/0x390 exportfs_decode_fh_raw+0x337/0x400 ? drop_caches_sysctl_handler+0xb0/0xb0 </TASK> ---[ end trace 0000000000000000 ]--- RIP: 0010:memcpy+0xc/0x10 Kernel panic - not syncing: Fatal exception [CAUSE] TThe crafted image has the following corrupted INODE_REF item: item 9 key (258 INODE_REF 257) itemoff 11544 itemsize 4106 index 2 namelen 4096 name: d\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000 The itemsize matches the namelen, but the namelen is 4096, way larger than normal name length limit (BTRFS_NAME_LEN, 255). Meanwhile the memory of the @name is only 255 byte sized, this will cause out-of-boundary access, and cause the above crash. [FIX] Add extra namelen verification for INODE_REF, just like what we have done in ROOT_REF checks. Now the crafted image can be rejected gracefully: BTRFS critical (device dm-2): corrupt leaf: root=5 block=30572544 slot=14 ino=259, invalid inode ref name length, has 4096 expect [1, 255] BTRFS error (device dm-2): read time tree block corruption detected on logical 30572544 mirror 2 [ Rebase, add a Link: tag, add an simple cause analyze ] | |
| Title | btrfs: tree-checker: validate INODE_REF's namelen | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-24T16:02:49.907Z
Reserved: 2026-09-18T17:59:28.790Z
Link: CVE-2026-93813
No data.
Status : Received
Published: 2026-09-24T17:17:14.763
Modified: 2026-09-24T17:17:14.763
Link: CVE-2026-93813
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.