The patch titled rmap: anon_vma_prepare() can leak anon_vma_chain has been removed from the -mm tree. Its filename was rmap-anon_vma_prepare-can-leak-anon_vma_chain.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: rmap: anon_vma_prepare() can leak anon_vma_chain From: Oleg Nesterov <oleg@xxxxxxxxxx> If find_mergeable_anon_vma() succeeds but another thread installs ->anon_vma before we take ptl, then allocated == NULL but avc should be freed. Change the code to check avc != NULL to detect this case. Also, a couple of whitespace changes to make the critical section more visible. Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Reviewed-by: Rik van Riel <riel@xxxxxxxxxx> Cc: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx> Cc: Pete Zaitcev <zaitcev@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/rmap.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff -puN mm/rmap.c~rmap-anon_vma_prepare-can-leak-anon_vma_chain mm/rmap.c --- a/mm/rmap.c~rmap-anon_vma_prepare-can-leak-anon_vma_chain +++ a/mm/rmap.c @@ -133,8 +133,8 @@ int anon_vma_prepare(struct vm_area_stru goto out_enomem_free_avc; allocated = anon_vma; } - spin_lock(&anon_vma->lock); + spin_lock(&anon_vma->lock); /* page_table_lock to protect against threads */ spin_lock(&mm->page_table_lock); if (likely(!vma->anon_vma)) { @@ -144,14 +144,15 @@ int anon_vma_prepare(struct vm_area_stru list_add(&avc->same_vma, &vma->anon_vma_chain); list_add(&avc->same_anon_vma, &anon_vma->head); allocated = NULL; + avc = NULL; } spin_unlock(&mm->page_table_lock); - spin_unlock(&anon_vma->lock); - if (unlikely(allocated)) { + + if (unlikely(allocated)) anon_vma_free(allocated); + if (unlikely(avc)) anon_vma_chain_free(avc); - } } return 0; _ Patches currently in -mm which might be from oleg@xxxxxxxxxx are origin.patch linux-next.patch cpu-timers-optimize-run_posix_cpu_timers.patch oom-select_bad_process-check-pf_kthread-instead-of-mm-to-skip-kthreads.patch oom-select_bad_process-pf_exiting-check-should-take-mm-into-account.patch oom-introduce-find_lock_task_mm-to-fix-mm-false-positives.patch oom-oom_forkbomb_penalty-move-thread_group_cputime-out-of-task_lock.patch oom-hold-tasklist_lock-when-dumping-tasks.patch oom-give-current-access-to-memory-reserves-if-it-has-been-killed.patch oom-avoid-sending-exiting-tasks-a-sigkill.patch oom-clean-up-oom_kill_task.patch oom-clean-up-oom_badness.patch oom-select_bad_process-never-choose-tasks-with-badness-==-0.patch kmod-add-init-function-to-usermodehelper.patch exec-replace-call_usermodehelper_pipe-with-use-of-umh-init-function-and-resolve-limit.patch umh-creds-convert-call_usermodehelper_keys-to-use-subprocess_info-init.patch umh-creds-kill-subprocess_info-cred-logic.patch call_usermodehelper-no-need-to-unblock-signals.patch wait_for_helper-sigchld-from-user-space-can-lead-to-use-after-free.patch call_usermodehelper-simplify-fix-umh_no_wait-case.patch call_usermodehelper-umh_wait_exec-ignores-kernel_thread-failure.patch coredump-factor-out-the-not-ispipe-file-checks.patch coredump-cleanup-ispipe-code.patch coredump-factor-out-put_cred-calls.patch coredump-shift-down_writemmap_sem-into-coredump_wait.patch exit-exit_notify-can-trust-signal-notify_count-0.patch exit-change-zap_other_threads-to-count-sub-threads.patch exit-avoid-sig-count-in-de_thread-__exit_signal-synchronization.patch exit-avoid-sig-count-in-__exit_signal-to-detect-the-group-dead-case.patch posix-cpu-timers-avoid-task-signal-=-null-checks.patch ia64-ptrace_attach_sync_user_rbs-avoid-task-signal-=-null-checks.patch fork-exit-move-tty_kref_put-outside-of-__cleanup_signal.patch signals-make-task_struct-signal-immutable-refcountable.patch signals-clear-signal-tty-when-the-last-thread-exits.patch signals-clear-signal-tty-when-the-last-thread-exits-fix.patch signals-kill-the-awful-task_rq_unlock_wait-hack.patch exit-__exit_signal-use-thread_group_leader-consistently.patch kill-the-obsolete-thread_group_cputime_free-and-taskstats_tgid_init-helpers.patch exit-move-taskstats_tgid_free-from-__exit_signal-to-free_signal_struct.patch check_unshare_flags-kill-the-bogus-clone_sighand-sig-count-check.patch proc-get_nr_threads-doesnt-need-siglock-any-longer.patch proc_sched_show_task-use-get_nr_threads.patch keyctl_session_to_parent-use-thread_group_empty-to-check-singlethreadness.patch proc-turn-signal_struct-count-into-int-nr_threads.patch proc-turn-signal_struct-count-into-int-nr_threads-checkpatch-fixes.patch proc-cleanup-remove-unused-assignments.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