CVE-2025-71183

CVE-2025-71183 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: always detect conflicting inodes when logging inode refs After rename exchanging (either with the rename exchange operation or regular renames in multiple non-atomic steps) two inodes and at least one of them is a directory, we can end up with a log tree that contains only of the inodes and after a power failure that can result in an attempt to delete the other inode when it should not because it was not deleted before the power failure. In some case that delete attempt fails when the target inode is a directory that contains a subvolume inside it, since the log replay code is not prepared to deal with directory entries that point to root items (only inode items). 1) We have directories "dir1" (inode A) and "dir2" (inode B) under the same parent directory; 2) We have a file (inode C) under directory "dir1" (inode A); 3) We have a subvolume inside directory "dir2" (inode B); 4) All these inodes were persisted in a past transaction and we are currently at transaction N; 5) We rename the file (inode C), so at btrfs_log_new_name() we update inode C's last_unlink_trans to N; 6) We get a rename exchange for "dir1" (inode A) and "dir2" (inode B), so after the exchange "dir1" is inode B and "dir2" is inode A. During the rename exchange we call btrfs_log_new_name() for inodes A and B, but because they are directories, we don't update their last_unlink_trans to N; 7) An fsync against the file (inode C) is done, and because its inode has a last_unlink_trans with a value of N we log its parent directory (inode A) (through btrfs_log_all_parents(), called from btrfs_log_inode_parent()). 8) So we end up with inode B not logged, which now has the old name of inode A. At copy_inode_items_to_log(), when logging inode A, we did not check if we had any conflicting inode to log because inode A has a generation lower than the current transaction (created in a past transaction); 9) After a power failure, when replaying the log tree, since we find that inode A has a new name that conflicts with the name of inode B in the fs tree, we attempt to delete inode B... this is wrong since that directory was never deleted before the power failure, and because there is a subvolume inside that directory, attempting to delete it will fail since replay_dir_deletes() and btrfs_unlink_inode() are not prepared to deal with dir items that point to roots instead of inodes. When that happens the mount fails and we get a stack trace like the following: [87.2314] BTRFS info (device dm-0): start tree-log replay [87.2318] BTRFS critical (device dm-0): failed to delete reference to subvol, root 5 inode 256 parent 259 [87.2332] ------------[ cut here ]------------ [87.2338] BTRFS: Transaction aborted (error -2) [87.2346] WARNING: CPU: 1 PID: 638968 at fs/btrfs/inode.c:4345 __btrfs_unlink_inode+0x416/0x440 [btrfs] [87.2368] Modules linked in: btrfs loop dm_thin_pool (...) [87.2470] CPU: 1 UID: 0 PID: 638968 Comm: mount Tainted: G W 6.18.0-rc7-btrfs-next-218+ #2 PREEMPT(full) [87.2489] Tainted: [W]=WARN [87.2494] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014 [87.2514] RIP: 0010:__btrfs_unlink_inode+0x416/0x440 [btrfs] [87.2538] Code: c0 89 04 24 (...) [87.2568] RSP: 0018:ffffc0e741f4b9b8 EFLAGS: 00010286 [87.2574] RAX: 0000000000000000 RBX: ffff9d3ec8a6cf60 RCX: 0000000000000000 [87.2582] RDX: 0000000000000002 RSI: ffffffff84ab45a1 RDI: 00000000ffffffff [87.2591] RBP: ffff9d3ec8a6ef20 R08: 0000000000000000 R09: ffffc0e741f4b840 [87.2599] R10: ffff9d45dc1fffa8 R11: 0000000000000003 R12: ffff9d3ee26d77e0 [87.2608] R13: ffffc0e741f4ba98 R14: ffff9d4458040800 R15: ffff9d44b6b7ca10 [87.2618] FS: 00007f7b9603a840(0000) GS:ffff9d4658982000(0000) knlGS:0000000000000000 [87. ---truncated---

Frequently asked questions

What is CVE-2025-71183?
In the Linux kernel, the following vulnerability has been resolved: btrfs: always detect conflicting inodes when logging inode refs After rename exchanging (either with the rename exchange operation or regular renames in multiple non-atomic steps) two inodes and at least one of them is a directory, we can end up with a log tree that contains only of the inodes and after a power failure that can result in an attempt to delete the other inode when it should not because it was not deleted before the power failure. In some case that delete attempt fails when the target inode is a directory that contains a subvolume inside it, since the log replay code is not prepared to deal with directory entries that point to root items (only inode items). 1) We have directories "dir1" (inode A) and "dir2" (inode B) under the same parent directory; 2) We have a file (inode C) under directory "dir1" (inode A); 3) We have a subvolume inside directory "dir2" (inode B); 4) All these inodes were persisted in a past transaction and we are currently at transaction N; 5) We rename the file (inode C), so at btrfs_log_new_name() we update inode C's last_unlink_trans to N; 6) We get a rename exchange for "dir1" (inode A) and "dir2" (inode B), so after the exchange "dir1" is inode B and "dir2" is inode A. During the rename exchange we call btrfs_log_new_name() for inodes A and B, but because they are directories, we don't update their last_unlink_trans to N; 7) An fsync against the file (inode C) is done, and because its inode has a last_unlink_trans with a value of N we log its parent directory (inode A) (through btrfs_log_all_parents(), called from btrfs_log_inode_parent()). 8) So we end up with inode B not logged, which now has the old name of inode A. At copy_inode_items_to_log(), when logging inode A, we did not check if we had any conflicting inode to log because inode A has a generation lower than the current transaction (created in a past transaction); 9) After a power failure, when replaying the log tree, since we find that inode A has a new name that conflicts with the name of inode B in the fs tree, we attempt to delete inode B... this is wrong since that directory was never deleted before the power failure, and because there is a subvolume inside that directory, attempting to delete it will fail since replay_dir_deletes() and btrfs_unlink_inode() are not prepared to deal with dir items that point to roots instead of inodes. When that happens the mount fails and we get a stack trace like the following: [87.2314] BTRFS info (device dm-0): start tree-log replay [87.2318] BTRFS critical (device dm-0): failed to delete reference to subvol, root 5 inode 256 parent 259 [87.2332] ------------[ cut here ]------------ [87.2338] BTRFS: Transaction aborted (error -2) [87.2346] WARNING: CPU: 1 PID: 638968 at fs/btrfs/inode.c:4345 __btrfs_unlink_inode+0x416/0x440 [btrfs] [87.2368] Modules linked in: btrfs loop dm_thin_pool (...) [87.2470] CPU: 1 UID: 0 PID: 638968 Comm: mount Tainted: G W 6.18.0-rc7-btrfs-next-218+ #2 PREEMPT(full) [87.2489] Tainted: [W]=WARN [87.2494] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014 [87.2514] RIP: 0010:__btrfs_unlink_inode+0x416/0x440 [btrfs] [87.2538] Code: c0 89 04 24 (...) [87.2568] RSP: 0018:ffffc0e741f4b9b8 EFLAGS: 00010286 [87.2574] RAX: 0000000000000000 RBX: ffff9d3ec8a6cf60 RCX: 0000000000000000 [87.2582] RDX: 0000000000000002 RSI: ffffffff84ab45a1 RDI: 00000000ffffffff [87.2591] RBP: ffff9d3ec8a6ef20 R08: 0000000000000000 R09: ffffc0e741f4b840 [87.2599] R10: ffff9d45dc1fffa8 R11: 0000000000000003 R12: ffff9d3ee26d77e0 [87.2608] R13: ffffc0e741f4ba98 R14: ffff9d4458040800 R15: ffff9d44b6b7ca10 [87.2618] FS: 00007f7b9603a840(0000) GS:ffff9d4658982000(0000) knlGS:0000000000000000 [87. ---truncated---
How severe is CVE-2025-71183?
CVE-2025-71183 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-71183 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-71183?
CVE-2025-71183 primarily affects Linux Linux Kernel. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-71183?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-71183 have an EU (EUVD) identifier?
Yes. CVE-2025-71183 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-206592.
When was CVE-2025-71183 published?
CVE-2025-71183 was published on 2026-01-31 and last updated on 2026-06-17.

References

Affected products (10)

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