CVE-2025-68818 in Linux
Summary
by MITRE • 01/13/2026
In the Linux kernel, the following vulnerability has been resolved:
scsi: Revert "scsi: qla2xxx: Perform lockless command completion in abort path"
This reverts commit 0367076b0817d5c75dfb83001ce7ce5c64d803a9.
The commit being reverted added code to __qla2x00_abort_all_cmds() to call sp->done() without holding a spinlock. But unlike the older code below it, this new code failed to check sp->cmd_type and just assumed TYPE_SRB, which results in a jump to an invalid pointer in target-mode with TYPE_TGT_CMD:
qla2xxx [0000:65:00.0]-d034:8: qla24xx_do_nack_work create sess success
0000000009f7a79b qla2xxx [0000:65:00.0]-5003:8: ISP System Error - mbx1=1ff5h mbx2=10h
mbx3=0h mbx4=0h mbx5=191h mbx6=0h mbx7=0h. qla2xxx [0000:65:00.0]-d01e:8: -> fwdump no buffer
qla2xxx [0000:65:00.0]-f03a:8: qla_target(0): System error async event
0x8002 occurred qla2xxx [0000:65:00.0]-00af:8: Performing ISP error recovery -
ha=0000000058183fda. BUG: kernel NULL pointer dereference, address: 0000000000000000 PF: supervisor instruction fetch in kernel mode PF: error_code(0x0010) - not-present page PGD 0 P4D 0 Oops: 0010 [#1] SMP
CPU: 2 PID: 9446 Comm: qla2xxx_8_dpc Tainted: G O 6.1.133 #1 Hardware name: Supermicro Super Server/X11SPL-F, BIOS 4.2 12/15/2023 RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0018:ffffc90001f93dc8 EFLAGS: 00010206 RAX: 0000000000000282 RBX: 0000000000000355 RCX: ffff88810d16a000 RDX: ffff88810dbadaa8 RSI: 0000000000080000 RDI: ffff888169dc38c0 RBP: ffff888169dc38c0 R08: 0000000000000001 R09: 0000000000000045 R10: ffffffffa034bdf0 R11: 0000000000000000 R12: ffff88810800bb40 R13: 0000000000001aa8 R14: ffff888100136610 R15: ffff8881070f7400 FS: 0000000000000000(0000) GS:ffff88bf80080000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000010c8ff006 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __die+0x4d/0x8b ? page_fault_oops+0x91/0x180 ? trace_buffer_unlock_commit_regs+0x38/0x1a0 ? exc_page_fault+0x391/0x5e0 ? asm_exc_page_fault+0x22/0x30 __qla2x00_abort_all_cmds+0xcb/0x3e0 [qla2xxx_scst]
qla2x00_abort_all_cmds+0x50/0x70 [qla2xxx_scst]
qla2x00_abort_isp_cleanup+0x3b7/0x4b0 [qla2xxx_scst]
qla2x00_abort_isp+0xfd/0x860 [qla2xxx_scst]
qla2x00_do_dpc+0x581/0xa40 [qla2xxx_scst]
kthread+0xa8/0xd0 </TASK>
Then commit 4475afa2646d ("scsi: qla2xxx: Complete command early within lock") added the spinlock back, because not having the lock caused a race and a crash. But qla2x00_abort_srb() in the switch below already checks for qla2x00_chip_is_down() and handles it the same way, so the code above the switch is now redundant and still buggy in target-mode. Remove it.
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Analysis
by VulDB Data Team • 07/16/2026
The vulnerability described in CVE-2025-68818 resides within the Linux kernel's SCSI subsystem, specifically within the qla2xxx driver that manages QLogic Fibre Channel HBAs. This issue stems from an improper handling of command completion during abort operations, which introduces a critical null pointer dereference. The flaw manifests when the driver attempts to complete commands in a target-mode configuration where different command types are processed. The root cause is traced to a reverted commit that removed necessary spinlock protection during command abortion, leading to a race condition and subsequent kernel panic.
The technical implementation flaw occurs in the `__qla2x00_abort_all_cmds()` function where the code calls `sp->done()` without proper locking mechanisms. Unlike previous implementations, this newer code fails to validate the `sp->cmd_type` field before assuming it is of `TYPE_SRB` type. In target-mode configurations with `TYPE_TGT_CMD` commands, this assumption leads to an invalid function pointer dereference, ultimately causing a kernel NULL pointer dereference. The kernel panic occurs during a supervisor instruction fetch operation, where the processor attempts to execute code at address zero, resulting in an immediate system crash and potential data loss.
This vulnerability has significant operational impact as it can cause complete system instability in environments using QLogic Fibre Channel HBAs, particularly in enterprise storage configurations where target-mode operations are common. The issue affects systems running kernel versions that include the problematic commit, potentially leading to unplanned system reboots, data corruption, and denial of service conditions in mission-critical storage infrastructure. The vulnerability aligns with CWE-476, which describes null pointer dereference issues, and represents a classic race condition problem that can be exploited to cause system crashes or potentially escalate privileges.
The mitigation strategy involves reverting the problematic commit and restoring proper spinlock protection around the command completion logic. The solution also requires ensuring that all command types are properly validated before function pointer dereference operations. Organizations should update their kernel versions to include the fixed commit that properly handles command type validation and maintains appropriate locking mechanisms. System administrators should monitor for kernel panic events and implement proper logging to detect potential exploitation attempts. This fix aligns with ATT&CK technique T1499.001 for network denial of service and addresses the underlying race condition that could be leveraged for system instability.
The vulnerability demonstrates the critical importance of proper locking mechanisms in kernel-space drivers, particularly when handling concurrent operations in storage subsystems. The removal of spinlock protection in a high-concurrency environment like SCSI target-mode creates a window for race conditions that can result in memory corruption. This issue highlights the need for comprehensive testing of driver code changes in multi-mode environments, particularly when switching between initiator and target configurations. Proper input validation and type checking of command structures are essential to prevent such critical failures in kernel drivers managing complex hardware interfaces.