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authorAl Viro <viro@zeniv.linux.org.uk>2015-04-06 17:57:44 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-04-19 10:11:09 +0200
commit6642619b3a74771f7ace0f0a653dde628815eaeb (patch)
treea8e54a956ee80a1a258b9c58573c990eec12f64d /fs
parentc82bd1171466bac9d9ab5c33896008bbdaf0aeb1 (diff)
downloadlinux-linaro-stable-6642619b3a74771f7ace0f0a653dde628815eaeb.tar.gz
ioctx_alloc(): fix vma (and file) leak on failure
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 <jmario@redhat.com>): 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 <jmario@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/aio.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 2f7e8c2e3e76..3241659491b1 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -719,6 +719,9 @@ 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);