{"id":"CVE-2026-74749","state":"PUBLISHED","title":"rseq: Prevent hard lockup on granted time slice extension","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrseq: Prevent hard lockup on granted time slice extension\n\n__exit_to_user_mode_loop() invokes rseq_grant_timeslice_extension() with\ninterrupts enabled. If the extension is granted it invokes\nhrtimer_rearm_deferred_tif() to ensure that a pending deferred hrtimer\nrearm is handled before exiting to user space.\n\nThough this invokes __hrtimer_rearm_deferred() which expects to be invoked\nwith interrupts disabled as it takes hrtimer_cpu_base::lock with\nraw_spin_lock(). That's a livelock waiting to happen and caught by lockdep:\n\n    WARNING: ./include/linux/hrtimer_rearm.h:17 at irqentry_exit, CPU#1: slice_test\n    WARNING: inconsistent lock state\n    inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.\n\nPrevent this by disabling interrupts around the invocation of\nhrtimer_rearm_deferred_tif() in rseq_grant_timeslice_extension().\n\n[ tglx: Massaged change log ]","publishedAt":"2026-08-26T14:36:57.763Z","updatedAt":"2026-08-26T14:36:57.763Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"15dd3a9488557d3e6ebcecacab79f4e56b69ab54","status":"affected","lessThan":"8bbf4405050bc4f98be68082a20efa081ea8ad9b","versionType":"git"},{"version":"15dd3a9488557d3e6ebcecacab79f4e56b69ab54","status":"affected","lessThan":"ada54c2ba652348c590d1ace6a2f4ff77cbbf809","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/rseq_entry.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"7.1.10","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/rseq_entry.h"]}],"references":["https://git.kernel.org/stable/c/8bbf4405050bc4f98be68082a20efa081ea8ad9b","https://git.kernel.org/stable/c/ada54c2ba652348c590d1ace6a2f4ff77cbbf809"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74749.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74749","state":"PUBLISHED","datePublished":"2026-08-26T14:36:57.763Z","dateUpdated":"2026-08-26T14:36:57.763Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.931Z"},"containers":{"cna":{"title":"rseq: Prevent hard lockup on granted time slice extension","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrseq: Prevent hard lockup on granted time slice extension\n\n__exit_to_user_mode_loop() invokes rseq_grant_timeslice_extension() with\ninterrupts enabled. If the extension is granted it invokes\nhrtimer_rearm_deferred_tif() to ensure that a pending deferred hrtimer\nrearm is handled before exiting to user space.\n\nThough this invokes __hrtimer_rearm_deferred() which expects to be invoked\nwith interrupts disabled as it takes hrtimer_cpu_base::lock with\nraw_spin_lock(). That's a livelock waiting to happen and caught by lockdep:\n\n    WARNING: ./include/linux/hrtimer_rearm.h:17 at irqentry_exit, CPU#1: slice_test\n    WARNING: inconsistent lock state\n    inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.\n\nPrevent this by disabling interrupts around the invocation of\nhrtimer_rearm_deferred_tif() in rseq_grant_timeslice_extension().\n\n[ tglx: Massaged change log ]"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"15dd3a9488557d3e6ebcecacab79f4e56b69ab54","status":"affected","lessThan":"8bbf4405050bc4f98be68082a20efa081ea8ad9b","versionType":"git"},{"version":"15dd3a9488557d3e6ebcecacab79f4e56b69ab54","status":"affected","lessThan":"ada54c2ba652348c590d1ace6a2f4ff77cbbf809","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/rseq_entry.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"7.1.10","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/rseq_entry.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/8bbf4405050bc4f98be68082a20efa081ea8ad9b"},{"url":"https://git.kernel.org/stable/c/ada54c2ba652348c590d1ace6a2f4ff77cbbf809"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-26T14:36:57.763Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.1.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}