CyberSecBulletin
CVE-2025-68818NVD status: Deferred

Linux: NULL Pointer Dereference

Published Updated By the CyberSecBulletin desk

CVE-2025-68818 is a high-severity NULL pointer dereference vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions b04b3733fff7e94566386b962e4795550fbdfd3d, 50b097d92c99f718831b8b349722bc79f718ba1b, c5c37a821bd1708f26a9522b4a6f47b9f7a20003 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.33% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to b04b3733fff7e94566386b962e4795550fbdfd3d or 50b097d92c99f718831b8b349722bc79f718ba1b or c5c37a821bd1708f26a9522b4a6f47b9f7a20003 or e9e601b7df58ba0c667baf30263331df2c02ffe1, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux231cfa78ec5badd84a1a2b09465bfad1a926aba1 up to, but not including, b04b3733fff7e94566386b962e4795550fbdfd3d; d6f7377528d2abf338e504126e44439541be8f7d up to, but not including, 50b097d92c99f718831b8b349722bc79f718ba1b; cd0a1804ac5bab2545ac700c8d0fe9ae9284c567 up to, but not including, c5c37a821bd1708f26a9522b4a6f47b9f7a20003; 0367076b0817d5c75dfb83001ce7ce5c64d803a9 up to, but not including, e9e601b7df58ba0c667baf30263331df2c02ffe1; 0367076b0817d5c75dfb83001ce7ce5c64d803a9 up to, but not including, b10ebbfd59a535c8d22f4ede6e8389622ce98dc0; 0367076b0817d5c75dfb83001ce7ce5c64d803a9 up to, but not including, 1c728951bc769b795d377852eae1abddad88635d; 0367076b0817d5c75dfb83001ce7ce5c64d803a9 up to, but not including, b57fbc88715b6d18f379463f48a15b560b087ffe; 9189f20b4c5307c0998682bb522e481b4567a8b8; and 7 more rangesb04b3733fff7e94566386b962e4795550fbdfd3d, 50b097d92c99f718831b8b349722bc79f718ba1b, c5c37a821bd1708f26a9522b4a6f47b9f7a20003, e9e601b7df58ba0c667baf30263331df2c02ffe1, b10ebbfd59a535c8d22f4ede6e8389622ce98dc0, 1c728951bc769b795d377852eae1abddad88635d
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)V3.1.6 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)V3.1.6 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)V3.1.6 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)V3.1.6 and later; V3.1.7 and laterNot stated
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)V3.1.6 and later; V3.1.7 and laterNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: NULL Pointer Dereference

The product dereferences a pointer that it expects to be valid but is NULL.

How developers prevent this class of flaw

  • For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
  • Select a programming language that is not susceptible to these issues.
  • Check the results of all functions that return a value and verify that the value is non-null before acting upon it.

More NULL Pointer Dereference vulnerabilities (CWE-476)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent NULL Pointer Dereference vulnerabilities

Spotted an error? Tell us.