Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030213AbbD0Vqi (ORCPT ); Mon, 27 Apr 2015 17:46:38 -0400 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:49615 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753223AbbD0Vc6 (ORCPT ); Mon, 27 Apr 2015 17:32:58 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Al Viro , Jiri Slaby Subject: [PATCH 3.12 43/83] ioctx_alloc(): fix vma (and file) leak on failure Date: Mon, 27 Apr 2015 23:32:14 +0200 Message-Id: X-Mailer: git-send-email 2.3.5 In-Reply-To: <3426bb8de3a655aa6668e92ee92eb35f0db86582.1430159990.git.jslaby@suse.cz> References: <3426bb8de3a655aa6668e92ee92eb35f0db86582.1430159990.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2198 Lines: 80 From: Al Viro 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit deeb8525f9bcea60f5e86521880c1161de7a5829 upstream. If we fail past the aio_setup_ring(), we need to destroy the mapping. We don't need to care about anybody having found ctx, or added requests to it, since the last failure exit is exactly the failure to make ctx visible to lookups. Reproducer (based on one by Joe Mario ): void count(char *p) { char s[80]; printf("%s: ", p); fflush(stdout); sprintf(s, "/bin/cat /proc/%d/maps|/bin/fgrep -c '/[aio] (deleted)'", getpid()); system(s); } int main() { io_context_t *ctx; int created, limit, i, destroyed; FILE *f; count("before"); if ((f = fopen("/proc/sys/fs/aio-max-nr", "r")) == NULL) perror("opening aio-max-nr"); else if (fscanf(f, "%d", &limit) != 1) fprintf(stderr, "can't parse aio-max-nr\n"); else if ((ctx = calloc(limit, sizeof(io_context_t))) == NULL) perror("allocating aio_context_t array"); else { for (i = 0, created = 0; i < limit; i++) { if (io_setup(1000, ctx + created) == 0) created++; } for (i = 0, destroyed = 0; i < created; i++) if (io_destroy(ctx[i]) == 0) destroyed++; printf("created %d, failed %d, destroyed %d\n", created, limit - created, destroyed); count("after"); } } Found-by: Joe Mario Signed-off-by: Al Viro Signed-off-by: Jiri Slaby --- fs/aio.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/aio.c b/fs/aio.c index 307d7708dc00..7bdf3467bf24 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -718,6 +718,9 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) err_cleanup: aio_nr_sub(ctx->max_reqs); err_ctx: + atomic_set(&ctx->dead, 1); + if (ctx->mmap_size) + vm_munmap(ctx->mmap_base, ctx->mmap_size); aio_free_ring(ctx); err: mutex_unlock(&ctx->ring_lock); -- 2.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/