{"id":"CVE-2025-40134","title":"dm: fix NULL pointer dereference in __dm_suspend()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm: fix NULL pointer dereference in __dm_suspend()\n\nThere is a race condition between dm device suspend and table load that\ncan lead to null pointer dereference. The is…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 9dc43ea6a20ff83fe9a5fe4be47ae0fbf2409b98","Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 30f95b7eda5966b81cb221bd569c0f095a068cf6","Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < a0e54bd8d7ea79127fe9920df3ae36f85e79ac7c","Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < a802901b75e13cc306f1b7ab0f062135c8034e9e","Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 846cafc4725ca727d94f9c4b5f789c1a7c8fb6fe","Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 19ca4528666990be376ac3eb6fe667b03db5324d","Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 331c2dd8ca8bad1a3ac10cce847ffb76158eece4","Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 8d33a030c566e1f105cd5bf27f37940b6367f3be","Linux 5.0"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T21:13:39.562413Z"},"published":"2025-11-12","updated":"2026-11-05","sourceUpdated":"2026-11-05T21:23:07.669Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-40134","references":[{"url":"https://git.kernel.org/stable/c/9dc43ea6a20ff83fe9a5fe4be47ae0fbf2409b98"},{"url":"https://git.kernel.org/stable/c/30f95b7eda5966b81cb221bd569c0f095a068cf6"},{"url":"https://git.kernel.org/stable/c/a0e54bd8d7ea79127fe9920df3ae36f85e79ac7c"},{"url":"https://git.kernel.org/stable/c/a802901b75e13cc306f1b7ab0f062135c8034e9e"},{"url":"https://git.kernel.org/stable/c/846cafc4725ca727d94f9c4b5f789c1a7c8fb6fe"},{"url":"https://git.kernel.org/stable/c/19ca4528666990be376ac3eb6fe667b03db5324d"},{"url":"https://git.kernel.org/stable/c/331c2dd8ca8bad1a3ac10cce847ffb76158eece4"},{"url":"https://git.kernel.org/stable/c/8d33a030c566e1f105cd5bf27f37940b6367f3be"}],"tags":["cve.org"],"epss":0.00227,"epssPercentile":0.1348,"ingestedAt":"2026-11-05T22:38:32.055Z","slug":"CVE-2025-40134","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ndm: fix NULL pointer dereference in __dm_suspend()\n\nThere is a race condition between dm device suspend and table load that\ncan lead to null pointer dereference. The issue occurs when suspend is\ninvoked before table load completes:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000054\nOops: 0000 [#1] PREEMPT SMP PTI\nCPU: 6 PID: 6798 Comm: dmsetup Not tainted 6.6.0-g7e52f5f0ca9b #62\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014\nRIP: 0010:blk_mq_wait_quiesce_done+0x0/0x50\nCall Trace:\n  <TASK>\n  blk_mq_quiesce_queue+0x2c/0x50\n  dm_stop_queue+0xd/0x20\n  __dm_suspend+0x130/0x330\n  dm_suspend+0x11a/0x180\n  dev_suspend+0x27e/0x560\n  ctl_ioctl+0x4cf/0x850\n  dm_ctl_ioctl+0xd/0x20\n  vfs_ioctl+0x1d/0x50\n  __se_sys_ioctl+0x9b/0xc0\n  __x64_sys_ioctl+0x19/0x30\n  x64_sys_call+0x2c4a/0x4620\n  do_syscall_64+0x9e/0x1b0\n\nThe issue can be triggered as below:\n\nT1 \t\t\t\t\t\tT2\ndm_suspend\t\t\t\t\ttable_load\n__dm_suspend\t\t\t\t\tdm_setup_md_queue\n\t\t\t\t\t\tdm_mq_init_request_queue\n\t\t\t\t\t\tblk_mq_init_allocated_queue\n\t\t\t\t\t\t=> q->mq_ops = set->ops; (1)\ndm_stop_queue / dm_wait_for_completion\n=> q->tag_set NULL pointer!\t(2)\n\t\t\t\t\t\t=> q->tag_set = set; (3)\n\nFix this by checking if a valid table (map) exists before performing\nrequest-based suspend and waiting for target I/O. When map is NULL,\nskip these table-dependent suspend steps.\n\nEven when map is NULL, no I/O can reach any target because there is\nno table loaded; I/O submitted in this state will fail early in the\nDM layer. Skipping the table-dependent suspend logic in this case\nis safe and avoids NULL pointer dereferences.\n\n## Affected\n\n- `Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 9dc43ea6a20ff83fe9a5fe4be47ae0fbf2409b98`\n- `Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 30f95b7eda5966b81cb221bd569c0f095a068cf6`\n- `Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < a0e54bd8d7ea79127fe9920df3ae36f85e79ac7c`\n- `Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < a802901b75e13cc306f1b7ab0f062135c8034e9e`\n- `Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 846cafc4725ca727d94f9c4b5f789c1a7c8fb6fe`\n- `Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 19ca4528666990be376ac3eb6fe667b03db5324d`\n- `Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 331c2dd8ca8bad1a3ac10cce847ffb76158eece4`\n- `Linux >= c4576aed8d85d808cd6443bda58393d525207d01 < 8d33a030c566e1f105cd5bf27f37940b6367f3be`\n- `Linux 5.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}