CVE-2023-53538

CVE-2023-53538 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. The underlying weakness is classified as CWE-476.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: insert tree mod log move in push_node_left There is a fairly unlikely race condition in tree mod log rewind that can result in a kernel panic which has the following trace: [530.569] BTRFS critical (device sda3): unable to find logical 0 length 4096 [530.585] BTRFS critical (device sda3): unable to find logical 0 length 4096 [530.602] BUG: kernel NULL pointer dereference, address: 0000000000000002 [530.618] #PF: supervisor read access in kernel mode [530.629] #PF: error_code(0x0000) - not-present page [530.641] PGD 0 P4D 0 [530.647] Oops: 0000 [#1] SMP [530.654] CPU: 30 PID: 398973 Comm: below Kdump: loaded Tainted: G S O K 5.12.0-0_fbk13_clang_7455_gb24de3bdb045 #1 [530.680] Hardware name: Quanta Mono Lake-M.2 SATA 1HY9U9Z001G/Mono Lake-M.2 SATA, BIOS F20_3A15 08/16/2017 [530.703] RIP: 0010:__btrfs_map_block+0xaa/0xd00 [530.755] RSP: 0018:ffffc9002c2f7600 EFLAGS: 00010246 [530.767] RAX: ffffffffffffffea RBX: ffff888292e41000 RCX: f2702d8b8be15100 [530.784] RDX: ffff88885fda6fb8 RSI: ffff88885fd973c8 RDI: ffff88885fd973c8 [530.800] RBP: ffff888292e410d0 R08: ffffffff82fd7fd0 R09: 00000000fffeffff [530.816] R10: ffffffff82e57fd0 R11: ffffffff82e57d70 R12: 0000000000000000 [530.832] R13: 0000000000001000 R14: 0000000000001000 R15: ffffc9002c2f76f0 [530.848] FS: 00007f38d64af000(0000) GS:ffff88885fd80000(0000) knlGS:0000000000000000 [530.866] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [530.880] CR2: 0000000000000002 CR3: 00000002b6770004 CR4: 00000000003706e0 [530.896] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [530.912] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [530.928] Call Trace: [530.934] ? btrfs_printk+0x13b/0x18c [530.943] ? btrfs_bio_counter_inc_blocked+0x3d/0x130 [530.955] btrfs_map_bio+0x75/0x330 [530.963] ? kmem_cache_alloc+0x12a/0x2d0 [530.973] ? btrfs_submit_metadata_bio+0x63/0x100 [530.984] btrfs_submit_metadata_bio+0xa4/0x100 [530.995] submit_extent_page+0x30f/0x360 [531.004] read_extent_buffer_pages+0x49e/0x6d0 [531.015] ? submit_extent_page+0x360/0x360 [531.025] btree_read_extent_buffer_pages+0x5f/0x150 [531.037] read_tree_block+0x37/0x60 [531.046] read_block_for_search+0x18b/0x410 [531.056] btrfs_search_old_slot+0x198/0x2f0 [531.066] resolve_indirect_ref+0xfe/0x6f0 [531.076] ? ulist_alloc+0x31/0x60 [531.084] ? kmem_cache_alloc_trace+0x12e/0x2b0 [531.095] find_parent_nodes+0x720/0x1830 [531.105] ? ulist_alloc+0x10/0x60 [531.113] iterate_extent_inodes+0xea/0x370 [531.123] ? btrfs_previous_extent_item+0x8f/0x110 [531.134] ? btrfs_search_path_in_tree+0x240/0x240 [531.146] iterate_inodes_from_logical+0x98/0xd0 [531.157] ? btrfs_search_path_in_tree+0x240/0x240 [531.168] btrfs_ioctl_logical_to_ino+0xd9/0x180 [531.179] btrfs_ioctl+0xe2/0x2eb0 This occurs when logical inode resolution takes a tree mod log sequence number, and then while backref walking hits a rewind on a busy node which has the following sequence of tree mod log operations (numbers filled in from a specific example, but they are somewhat arbitrary) REMOVE_WHILE_FREEING slot 532 REMOVE_WHILE_FREEING slot 531 REMOVE_WHILE_FREEING slot 530 ... REMOVE_WHILE_FREEING slot 0 REMOVE slot 455 REMOVE slot 454 REMOVE slot 453 ... REMOVE slot 0 ADD slot 455 ADD slot 454 ADD slot 453 ... ADD slot 0 MOVE src slot 0 -> dst slot 456 nritems 533 REMOVE slot 455 REMOVE slot 454 REMOVE slot 453 ... REMOVE slot 0 When this sequence gets applied via btrfs_tree_mod_log_rewind, it allocates a fresh rewind eb, and first inserts the correct key info for the 533 elements, then overwrites the first 456 of them, then decrements the count by 456 via the add ops, then rewinds the move by doing a memmove from 456:988->0:532. We have never written anything past 532, ---truncated---

Frequently asked questions

What is CVE-2023-53538?
In the Linux kernel, the following vulnerability has been resolved: btrfs: insert tree mod log move in push_node_left There is a fairly unlikely race condition in tree mod log rewind that can result in a kernel panic which has the following trace: [530.569] BTRFS critical (device sda3): unable to find logical 0 length 4096 [530.585] BTRFS critical (device sda3): unable to find logical 0 length 4096 [530.602] BUG: kernel NULL pointer dereference, address: 0000000000000002 [530.618] #PF: supervisor read access in kernel mode [530.629] #PF: error_code(0x0000) - not-present page [530.641] PGD 0 P4D 0 [530.647] Oops: 0000 [#1] SMP [530.654] CPU: 30 PID: 398973 Comm: below Kdump: loaded Tainted: G S O K 5.12.0-0_fbk13_clang_7455_gb24de3bdb045 #1 [530.680] Hardware name: Quanta Mono Lake-M.2 SATA 1HY9U9Z001G/Mono Lake-M.2 SATA, BIOS F20_3A15 08/16/2017 [530.703] RIP: 0010:__btrfs_map_block+0xaa/0xd00 [530.755] RSP: 0018:ffffc9002c2f7600 EFLAGS: 00010246 [530.767] RAX: ffffffffffffffea RBX: ffff888292e41000 RCX: f2702d8b8be15100 [530.784] RDX: ffff88885fda6fb8 RSI: ffff88885fd973c8 RDI: ffff88885fd973c8 [530.800] RBP: ffff888292e410d0 R08: ffffffff82fd7fd0 R09: 00000000fffeffff [530.816] R10: ffffffff82e57fd0 R11: ffffffff82e57d70 R12: 0000000000000000 [530.832] R13: 0000000000001000 R14: 0000000000001000 R15: ffffc9002c2f76f0 [530.848] FS: 00007f38d64af000(0000) GS:ffff88885fd80000(0000) knlGS:0000000000000000 [530.866] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [530.880] CR2: 0000000000000002 CR3: 00000002b6770004 CR4: 00000000003706e0 [530.896] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [530.912] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [530.928] Call Trace: [530.934] ? btrfs_printk+0x13b/0x18c [530.943] ? btrfs_bio_counter_inc_blocked+0x3d/0x130 [530.955] btrfs_map_bio+0x75/0x330 [530.963] ? kmem_cache_alloc+0x12a/0x2d0 [530.973] ? btrfs_submit_metadata_bio+0x63/0x100 [530.984] btrfs_submit_metadata_bio+0xa4/0x100 [530.995] submit_extent_page+0x30f/0x360 [531.004] read_extent_buffer_pages+0x49e/0x6d0 [531.015] ? submit_extent_page+0x360/0x360 [531.025] btree_read_extent_buffer_pages+0x5f/0x150 [531.037] read_tree_block+0x37/0x60 [531.046] read_block_for_search+0x18b/0x410 [531.056] btrfs_search_old_slot+0x198/0x2f0 [531.066] resolve_indirect_ref+0xfe/0x6f0 [531.076] ? ulist_alloc+0x31/0x60 [531.084] ? kmem_cache_alloc_trace+0x12e/0x2b0 [531.095] find_parent_nodes+0x720/0x1830 [531.105] ? ulist_alloc+0x10/0x60 [531.113] iterate_extent_inodes+0xea/0x370 [531.123] ? btrfs_previous_extent_item+0x8f/0x110 [531.134] ? btrfs_search_path_in_tree+0x240/0x240 [531.146] iterate_inodes_from_logical+0x98/0xd0 [531.157] ? btrfs_search_path_in_tree+0x240/0x240 [531.168] btrfs_ioctl_logical_to_ino+0xd9/0x180 [531.179] btrfs_ioctl+0xe2/0x2eb0 This occurs when logical inode resolution takes a tree mod log sequence number, and then while backref walking hits a rewind on a busy node which has the following sequence of tree mod log operations (numbers filled in from a specific example, but they are somewhat arbitrary) REMOVE_WHILE_FREEING slot 532 REMOVE_WHILE_FREEING slot 531 REMOVE_WHILE_FREEING slot 530 ... REMOVE_WHILE_FREEING slot 0 REMOVE slot 455 REMOVE slot 454 REMOVE slot 453 ... REMOVE slot 0 ADD slot 455 ADD slot 454 ADD slot 453 ... ADD slot 0 MOVE src slot 0 -> dst slot 456 nritems 533 REMOVE slot 455 REMOVE slot 454 REMOVE slot 453 ... REMOVE slot 0 When this sequence gets applied via btrfs_tree_mod_log_rewind, it allocates a fresh rewind eb, and first inserts the correct key info for the 533 elements, then overwrites the first 456 of them, then decrements the count by 456 via the add ops, then rewinds the move by doing a memmove from 456:988->0:532. We have never written anything past 532, ---truncated---
How severe is CVE-2023-53538?
CVE-2023-53538 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-2023-53538 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-53538?
CVE-2023-53538 primarily affects Linux Linux Kernel. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-53538?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2023-53538 have an EU (EUVD) identifier?
Yes. CVE-2023-53538 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-32354.
When was CVE-2023-53538 published?
CVE-2023-53538 was published on 2025-10-04 and last updated on 2026-06-17.

References

Affected products (8)

More vulnerabilities in Linux Linux Kernel

All CVEs affecting Linux Linux Kernel →

Other CWE-476 (NULL Pointer Dereference) vulnerabilities

Browse all CWE-476 (NULL Pointer Dereference) vulnerabilities →