{"id":"CVE-2026-74749","summary":"rseq: Prevent hard lockup on granted time slice extension","details":"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} -\u003e {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 ]","modified":"2026-08-28T11:48:23.502742745Z","published":"2026-08-26T14:36:57.763Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74749.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/8bbf4405050bc4f98be68082a20efa081ea8ad9b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ada54c2ba652348c590d1ace6a2f4ff77cbbf809"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74749.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74749"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"15dd3a9488557d3e6ebcecacab79f4e56b69ab54"},{"fixed":"8bbf4405050bc4f98be68082a20efa081ea8ad9b"},{"fixed":"ada54c2ba652348c590d1ace6a2f4ff77cbbf809"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74749.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.1.0"},{"fixed":"7.1.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74749.json"}}],"schema_version":"1.9.0"}