The patch titled Subject: block: use for_each_thread() in sys_ioprio_set()/sys_ioprio_get() has been added to the -mm tree. Its filename is block-use-for_each_thread-in-sys_ioprio_set-sys_ioprio_get.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/block-use-for_each_thread-in-sys_ioprio_set-sys_ioprio_get.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/block-use-for_each_thread-in-sys_ioprio_set-sys_ioprio_get.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Subject: block: use for_each_thread() in sys_ioprio_set()/sys_ioprio_get() IOPRIO_WHO_USER case in sys_ioprio_set()/sys_ioprio_get() are using while_each_thread(), which is unsafe under RCU lock according to commit 0c740d0afc3bff0a ("introduce for_each_thread() to replace the buggy while_each_thread()"). Use for_each_thread() (via for_each_process_thread()) which is safe under RCU lock. Link: http://lkml.kernel.org/r/201702011947.DBD56740.OMVHOLOtSJFFFQ@xxxxxxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/1486041779-4401-1-git-send-email-penguin-kernel@xxxxxxxxxxxxxxxxxxx Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- block/ioprio.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff -puN block/ioprio.c~block-use-for_each_thread-in-sys_ioprio_set-sys_ioprio_get block/ioprio.c --- a/block/ioprio.c~block-use-for_each_thread-in-sys_ioprio_set-sys_ioprio_get +++ a/block/ioprio.c @@ -122,14 +122,14 @@ SYSCALL_DEFINE3(ioprio_set, int, which, if (!user) break; - do_each_thread(g, p) { + for_each_process_thread(g, p) { if (!uid_eq(task_uid(p), uid) || !task_pid_vnr(p)) continue; ret = set_task_ioprio(p, ioprio); if (ret) goto free_uid; - } while_each_thread(g, p); + } free_uid: if (who) free_uid(user); @@ -222,7 +222,7 @@ SYSCALL_DEFINE2(ioprio_get, int, which, if (!user) break; - do_each_thread(g, p) { + for_each_process_thread(g, p) { if (!uid_eq(task_uid(p), user->uid) || !task_pid_vnr(p)) continue; @@ -233,7 +233,7 @@ SYSCALL_DEFINE2(ioprio_get, int, which, ret = tmpio; else ret = ioprio_best(ret, tmpio); - } while_each_thread(g, p); + } if (who) free_uid(user); _ Patches currently in -mm which might be from penguin-kernel@xxxxxxxxxxxxxxxxxxx are block-use-for_each_thread-in-sys_ioprio_set-sys_ioprio_get.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html