{"id":"CVE-2026-98072","published":"2026-09-25T11:17:36.450","lastModified":"2026-09-25T11:17:36.450","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: use wq_has_sleeper() in release_in_xmit()\n\nrelease_in_xmit() clears RDS_IN_XMIT with clear_bit_unlock() and then\nchecks waitqueue_active() to decide whether anyone needs waking.\nclear_bit_unlock() is only a release operation: it orders the\ncritical section before the bit clear, but does not order the\nsubsequent plain load of the wait queue head after it.  The waiter\nside does the mirror image - it adds itself to the wait queue and\nthen tests the bit.  That is the classic store-buffering pattern: the\nreleasing CPU can read the wait queue as empty while the waiting CPU\nstill reads the bit as set, so the sleeper is never woken.\n\nThe waiters are rds_conn_shutdown() and rds_tcp_reset_callbacks(),\nboth in uninterruptible wait_event() with no timeout.  A lost wake-up\nstrands the shutdown worker on its single-threaded workqueue until\nsome other sender releases the bit again - and on a connection that\nis being torn down precisely because it failed, there may never be\nanother sender.\n\nThe barrier used to be there: release_in_xmit() did clear_bit()\nfollowed by smp_mb__after_atomic() until commit 1422f28826d2 (\"rds:\nintroduce acquire/release ordering in acquire/release_in_xmit()\")\nfolded both into clear_bit_unlock(), which strengthened the lock\nhand-off but silently dropped the full barrier the wake-up check\ndepends on.  The refill counterpart, release_refill() in\nnet/rds/ib_recv.c, still carries its smp_mb__after_atomic() for\nexactly this reason.\n\nUse wq_has_sleeper(), which is waitqueue_active() preceded by the\nrequired full barrier.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/3764627b30a283e611e652c4a2bb8cdc74a75a99","tags":[]},{"url":"https://git.kernel.org/stable/c/6d0c8b7073913011459cf968cbbadd341e166bc3","tags":[]},{"url":"https://git.kernel.org/stable/c/a269795107f45adc95975a83324f8fef40bec4ce","tags":[]},{"url":"https://git.kernel.org/stable/c/ed7ee0cd0e136d02f87f13181b1a89880463c7e9","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}