# CVE-2025-21752: linux: In the Linux kernel, the following vulnerability has been resolved:  btrfs: don't use btrfs_set_item_key_safe on RAID...

CVE-2025-21752 is fixed in linux on 1 platform by DEBIAN-CVE-2025-21752 (version 6.16.3-1), released February 27, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2025-21752
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 27, 2025

## Description

In the Linux kernel, the following vulnerability has been resolved:  btrfs: don't use btrfs_set_item_key_safe on RAID stripe-extents  Don't use btrfs_set_item_key_safe() to modify the keys in the RAID stripe-tree, as this can lead to corruption of the tree, which is caught by the checks in btrfs_set_item_key_safe():   BTRFS info (device nvme1n1): leaf 49168384 gen 15 total ptrs 194 free space 8329 owner 12  BTRFS info (device nvme1n1): refs 2 lock_owner 1030 current 1030   [ snip ]   item 105 key (354549760 230 20480) itemoff 14587 itemsize 16                   stride 0 devid 5 physical 67502080   item 106 key (354631680 230 4096) itemoff 14571 itemsize 16                   stride 0 devid 1 physical 88559616   item 107 key (354631680 230 32768) itemoff 14555 itemsize 16                   stride 0 devid 1 physical 88555520   item 108 key (354717696 230 28672) itemoff 14539 itemsize 16                   stride 0 devid 2 physical 67604480   [ snip ]  BTRFS critical (device nvme1n1): slot 106 key (354631680 230 32768) new key (354635776 230 4096)  ------------[ cut here ]------------  kernel BUG at fs/btrfs/ctree.c:2602!  Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI  CPU: 1 UID: 0 PID: 1055 Comm: fsstress Not tainted 6.13.0-rc1+ #1464  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014  RIP: 0010:btrfs_set_item_key_safe+0xf7/0x270  Code: <snip>  RSP: 0018:ffffc90001337ab0 EFLAGS: 00010287  RAX: 0000000000000000 RBX: ffff8881115fd000 RCX: 0000000000000000  RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00000000ffffffff  RBP: ffff888110ed6f50 R08: 00000000ffffefff R09: ffffffff8244c500  R10: 00000000ffffefff R11: 00000000ffffffff R12: ffff888100586000  R13: 00000000000000c9 R14: ffffc90001337b1f R15: ffff888110f23b58  FS:  00007f7d75c72740(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033  CR2: 00007fa811652c60 CR3: 0000000111398001 CR4: 0000000000370eb0  Call Trace:   <TASK>   ? __die_body.cold+0x14/0x1a   ? die+0x2e/0x50   ? do_trap+0xca/0x110   ? do_error_trap+0x65/0x80   ? btrfs_set_item_key_safe+0xf7/0x270   ? exc_invalid_op+0x50/0x70   ? btrfs_set_item_key_safe+0xf7/0x270   ? asm_exc_invalid_op+0x1a/0x20   ? btrfs_set_item_key_safe+0xf7/0x270   btrfs_partially_delete_raid_extent+0xc4/0xe0   btrfs_delete_raid_extent+0x227/0x240   __btrfs_free_extent.isra.0+0x57f/0x9c0   ? exc_coproc_segment_overrun+0x40/0x40   __btrfs_run_delayed_refs+0x2fa/0xe80   btrfs_run_delayed_refs+0x81/0xe0   btrfs_commit_transaction+0x2dd/0xbe0   ? preempt_count_add+0x52/0xb0   btrfs_sync_file+0x375/0x4c0   do_fsync+0x39/0x70   __x64_sys_fsync+0x13/0x20   do_syscall_64+0x54/0x110   entry_SYSCALL_64_after_hwframe+0x76/0x7e  RIP: 0033:0x7f7d7550ef90  Code: <snip>  RSP: 002b:00007ffd70237248 EFLAGS: 00000202 ORIG_RAX: 000000000000004a  RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f7d7550ef90  RDX: 000000000000013a RSI: 000000000040eb28 RDI: 0000000000000004  RBP: 000000000000001b R08: 0000000000000078 R09: 00007ffd7023725c  R10: 00007f7d75400390 R11: 0000000000000202 R12: 028f5c28f5c28f5c  R13: 8f5c28f5c28f5c29 R14: 000000000040b520 R15: 00007f7d75c726c8   </TASK>  While the root cause of the tree order corruption isn't clear, using btrfs_duplicate_item() to copy the item and then adjusting both the key and the per-device physical addresses is a safe way to counter this problem.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 6.16.3-1 | [DEBIAN-CVE-2025-21752](https://patchblox.com/security/data/fix/linux/debian-cve-2025-21752.md) | Feb 27, 2025 |

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