From: Usama Arif <usama.arif@linux.dev> mainline inclusion from mainline-v7.2-rc1 commit fd38b75c4b43295b10d69772a46d1c74dbd6fc81 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9506 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- PF_BLOCK_TS is only set in blk_time_get_ns() when current->plug is non-NULL, and blk_finish_plug() clears it via __blk_flush_plug() before NULLing the plug pointer. copy_process() breaks the invariant by inheriting PF_BLOCK_TS from the parent while resetting the child's plug to NULL. Clear PF_BLOCK_TS alongside that assignment so callers can rely on "PF_BLOCK_TS set implies current->plug != NULL" and dereference current->plug unguarded. Fixes: 06b23f92af87 ("block: update cached timestamp post schedule/preemption") Cc: stable@vger.kernel.org Signed-off-by: Usama Arif <usama.arif@linux.dev> Link: https://patch.msgid.link/20260616141604.328820-2-usama.arif@linux.dev Signed-off-by: Jens Axboe <axboe@kernel.dk> Conflicts: kernel/fork.c [context conflict] Signed-off-by: Chen Jinghuang <chenjinghuang2@huawei.com> --- kernel/fork.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/fork.c b/kernel/fork.c index 02b676d10054..fce021bf136a 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2051,6 +2051,7 @@ static __latent_entropy struct task_struct *copy_process( #ifdef CONFIG_BLOCK p->plug = NULL; + p->flags &= ~PF_BLOCK_TS; #endif futex_init_task(p); p->futex_exit_mutex = kmalloc(sizeof(struct mutex), GFP_KERNEL); -- 2.34.1