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authorJerome Marchand <jmarchan@redhat.com>2016-01-15 16:54:48 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-17 12:31:06 -0800
commitaee0848f2e83f9a2a6acfcae0cdd411a8e8222f9 (patch)
tree34cf9a79b122349519a04cef8d19fc0dad126c6d /drivers/block
parent73f6736093323247103ad59ef04676ea2bb000c7 (diff)
zram: don't call idr_remove() from zram_remove()
commit 17ec4cd985780a7e30aa45bb8f272237c12502a4 upstream. The use of idr_remove() is forbidden in the callback functions of idr_for_each(). It is therefore unsafe to call idr_remove in zram_remove(). This patch moves the call to idr_remove() from zram_remove() to hot_remove_store(). In the detroy_devices() path, idrs are removed by idr_destroy(). This solves an use-after-free detected by KASan. [akpm@linux-foundation.org: fix coding stype, per Sergey] Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/zram/zram_drv.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 47915d736f8d..370c2f76016d 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1325,7 +1325,6 @@ static int zram_remove(struct zram *zram)
pr_info("Removed device: %s\n", zram->disk->disk_name);
- idr_remove(&zram_index_idr, zram->disk->first_minor);
blk_cleanup_queue(zram->disk->queue);
del_gendisk(zram->disk);
put_disk(zram->disk);
@@ -1367,10 +1366,12 @@ static ssize_t hot_remove_store(struct class *class,
mutex_lock(&zram_index_mutex);
zram = idr_find(&zram_index_idr, dev_id);
- if (zram)
+ if (zram) {
ret = zram_remove(zram);
- else
+ idr_remove(&zram_index_idr, dev_id);
+ } else {
ret = -ENODEV;
+ }
mutex_unlock(&zram_index_mutex);
return ret ? ret : count;