The patch titled Subject: posix-timer: don't call idr_find() w/ out-of-range ID has been added to the -mm tree. Its filename is posix-timer-dont-call-idr_find-w-out-of-range-id.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: Tejun Heo <tj@xxxxxxxxxx> Subject: posix-timer: don't call idr_find() w/ out-of-range ID When idr_find() is fed a negative ID, it used to look up the ID ignoring the sign bit before recent ("idr: remove MAX_IDR_MASK and move left MAX_IDR_* into idr.c") patch, and triggers WARN_ON_ONCE() after it. __lock_timer() feeds timer_id from userland directly to idr_find() without sanitizing it which can trigger the above malfunctions. Add a range check on @timer_id before invoking idr_find() in __lock_timer(). While timer_t is defined as int by all archs at the moment, Andrew worries that it may be defined as a larger type later on. Make the test cover larger integers too so that it at least is guaranteed to not return the wrong timer. Note that WARN_ON_ONCE() in idr_find() on id < 0 is transitional precaution while moving away from ignoring MSB. Once it's gone we can remove the guard as long as timer_t isn't larger than int. Given that larger timer_t is possible, at least theoretically, it probably is better to keep the guard even if idr_find() is later updated, so not marking the guard as to be removed. Will send a separate patch to add comment on top of WARN_ON_ONCE() in idr_find(). Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/posix-timers.c | 7 +++++++ 1 file changed, 7 insertions(+) diff -puN kernel/posix-timers.c~posix-timer-dont-call-idr_find-w-out-of-range-id kernel/posix-timers.c --- a/kernel/posix-timers.c~posix-timer-dont-call-idr_find-w-out-of-range-id +++ a/kernel/posix-timers.c @@ -639,6 +639,13 @@ static struct k_itimer *__lock_timer(tim { struct k_itimer *timr; + /* + * timer_t could be any type >= int and we want to make sure any + * @timer_id outside positive int range fails lookup. + */ + if ((unsigned long long)timer_id > INT_MAX) + return NULL; + rcu_read_lock(); timr = idr_find(&posix_timers_id, (int)timer_id); if (timr) { _ Patches currently in -mm which might be from tj@xxxxxxxxxx are origin.patch device_cgroup-dont-grab-mutex-in-rcu-callback.patch linux-next.patch cfq-fix-lock-imbalance-with-failed-allocations.patch block-restore-proc-partitions-to-not-display-non-partitionable-removable-devices.patch memcg-do-not-create-memsw-files-if-swap-accounting-is-disabled.patch memcg-clean-up-swap-accounting-initialization-code.patch memcg-prevent-changes-to-move_charge_at_immigrate-during-task-attach.patch memcg-split-part-of-memcg-creation-to-css_online.patch memcg-fast-hierarchy-aware-child-test.patch memcg-fast-hierarchy-aware-child-test-fix.patch memcg-fast-hierarchy-aware-child-test-fix-fix.patch memcg-replace-cgroup_lock-with-memcg-specific-memcg_lock.patch memcg-replace-cgroup_lock-with-memcg-specific-memcg_lock-fix.patch memcg-increment-static-branch-right-after-limit-set.patch memcg-avoid-dangling-reference-count-in-creation-failure.patch lib-scatterlist-add-simple-page-iterator.patch lib-scatterlist-use-page-iterator-in-the-mapping-iterator.patch coredump-only-sigkill-should-interrupt-the-coredumping-task.patch coredump-ensure-that-sigkill-always-kills-the-dumping-thread.patch coredump-sanitize-the-setting-of-signal-group_exit_code.patch vfork-dont-freezer_count-for-in-kernel-users-of-clone_vfork.patch lockdep-check-that-no-locks-held-at-freeze-time.patch lockdep-check-that-no-locks-held-at-freeze-time-fix.patch coredump-cleanup-the-waiting-for-coredump_finish-code.patch coredump-use-a-freezable_schedule-for-the-coredump_finish-wait.patch coredump-abort-core-dump-piping-only-due-to-a-fatal-signal.patch idr-fix-a-subtle-bug-in-idr_get_next.patch idr-make-idr_destroy-imply-idr_remove_all.patch atm-nicstar-dont-use-idr_remove_all.patch block-loop-dont-use-idr_remove_all.patch firewire-dont-use-idr_remove_all.patch drm-dont-use-idr_remove_all.patch dm-dont-use-idr_remove_all.patch remoteproc-dont-use-idr_remove_all.patch rpmsg-dont-use-idr_remove_all.patch dlm-use-idr_for_each_entry-in-recover_idr_clear-error-path.patch dlm-dont-use-idr_remove_all.patch nfs-idr_destroy-no-longer-needs-idr_remove_all.patch inotify-dont-use-idr_remove_all.patch cgroup-dont-use-idr_remove_all.patch nfsd-idr_destroy-no-longer-needs-idr_remove_all.patch idr-deprecate-idr_remove_all.patch idr-cosmetic-updates-to-struct-initializer-definitions.patch idr-relocate-idr_for_each_entry-and-reorganize-id_get_new.patch idr-remove-_idr_rc_to_errno-hack.patch idr-refactor-idr_get_new_above.patch idr-implement-idr_preload-and-idr_alloc.patch idr-implement-idr_preload-and-idr_alloc-fix.patch block-fix-synchronization-and-limit-check-in-blk_alloc_devt.patch block-convert-to-idr_alloc.patch block-loop-convert-to-idr_alloc.patch atm-nicstar-convert-to-idr_alloc.patch drbd-convert-to-idr_alloc.patch dca-convert-to-idr_alloc.patch dmaengine-convert-to-idr_alloc.patch firewire-add-minor-number-range-check-to-fw_device_init.patch firewire-convert-to-idr_alloc.patch firewire-convert-to-idr_alloc-fix.patch gpio-convert-to-idr_alloc.patch drm-convert-to-idr_alloc.patch drm-convert-to-idr_alloc-fix.patch drm-convert-to-idr_alloc-fix-fix.patch drm-exynos-convert-to-idr_alloc.patch drm-i915-convert-to-idr_alloc.patch drm-sis-convert-to-idr_alloc.patch drm-via-convert-to-idr_alloc.patch drm-vmwgfx-convert-to-idr_alloc.patch i2c-convert-to-idr_alloc.patch i2c-convert-to-idr_alloc-fix.patch i2c-convert-to-idr_alloc-fix-fix.patch ib-core-convert-to-idr_alloc.patch ib-amso1100-convert-to-idr_alloc.patch ib-cxgb3-convert-to-idr_alloc.patch ib-cxgb4-convert-to-idr_alloc.patch ib-ehca-convert-to-idr_alloc.patch ib-ipath-convert-to-idr_alloc.patch ib-mlx4-convert-to-idr_alloc.patch ib-ocrdma-convert-to-idr_alloc.patch ib-qib-convert-to-idr_alloc.patch dm-convert-to-idr_alloc.patch memstick-convert-to-idr_alloc.patch mfd-convert-to-idr_alloc.patch misc-c2port-convert-to-idr_alloc.patch misc-tifm_core-convert-to-idr_alloc.patch mmc-convert-to-idr_alloc.patch mtd-convert-to-idr_alloc.patch macvtap-convert-to-idr_alloc.patch ppp-convert-to-idr_alloc.patch power-convert-to-idr_alloc.patch pps-convert-to-idr_alloc.patch remoteproc-convert-to-idr_alloc.patch rpmsg-convert-to-idr_alloc.patch scsi-bfa-convert-to-idr_alloc.patch scsi-convert-to-idr_alloc.patch target-iscsi-convert-to-idr_alloc.patch scsi-lpfc-convert-to-idr_alloc.patch thermal-convert-to-idr_alloc.patch uio-convert-to-idr_alloc.patch vfio-convert-to-idr_alloc.patch dlm-convert-to-idr_alloc.patch inotify-convert-to-idr_alloc.patch ocfs2-convert-to-idr_alloc.patch ipc-convert-to-idr_alloc.patch ipc-convert-to-idr_alloc-fix.patch cgroup-convert-to-idr_alloc.patch events-convert-to-idr_alloc.patch posix-timer-dont-call-idr_find-w-out-of-range-id.patch posix-timers-convert-to-idr_alloc.patch net-9p-convert-to-idr_alloc.patch mac80211-convert-to-idr_alloc.patch sctp-convert-to-idr_alloc.patch nfs4client-convert-to-idr_alloc.patch idr-fix-top-layer-handling.patch idr-remove-max_idr_mask-and-move-left-max_idr_-into-idrc.patch idr-remove-length-restriction-from-idr_layer-bitmap.patch idr-remove-length-restriction-from-idr_layer-bitmap-checkpatch-fixes.patch idr-make-idr_layer-larger.patch idr-add-idr_layer-prefix.patch idr-implement-lookup-hint.patch idr-implement-lookup-hint-always-do-slow-path-when-hint-is-uninitialized.patch hlist-drop-the-node-parameter-from-iterators-fix-fix-fix-fix.patch hlist-drop-the-node-parameter-from-iterators-fix-fix-fix.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