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| author | Minchan Kim <minchan@kernel.org> | 2018-12-28 00:36:37 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-13 10:01:02 +0100 |
| commit | ce8daa28a1d53dcf4258cff2b559d7ad37325dfa (patch) | |
| tree | d0bcf26e9b82c27c4ca01689c909e7655d32621f /drivers/block | |
| parent | 3f2e4e1d9a6cffa95d31b7a491243d5e92a82507 (diff) | |
| download | linux-stable-ce8daa28a1d53dcf4258cff2b559d7ad37325dfa.tar.gz linux-stable-ce8daa28a1d53dcf4258cff2b559d7ad37325dfa.tar.bz2 linux-stable-ce8daa28a1d53dcf4258cff2b559d7ad37325dfa.zip | |
zram: fix double free backing device
commit 5547932dc67a48713eece4fa4703bfdf0cfcb818 upstream.
If blkdev_get fails, we shouldn't do blkdev_put. Otherwise, kernel emits
below log. This patch fixes it.
WARNING: CPU: 0 PID: 1893 at fs/block_dev.c:1828 blkdev_put+0x105/0x120
Modules linked in:
CPU: 0 PID: 1893 Comm: swapoff Not tainted 4.19.0+ #453
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
RIP: 0010:blkdev_put+0x105/0x120
Call Trace:
__x64_sys_swapoff+0x46d/0x490
do_syscall_64+0x5a/0x190
entry_SYSCALL_64_after_hwframe+0x49/0xbe
irq event stamp: 4466
hardirqs last enabled at (4465): __free_pages_ok+0x1e3/0x490
hardirqs last disabled at (4466): trace_hardirqs_off_thunk+0x1a/0x1c
softirqs last enabled at (3420): __do_softirq+0x333/0x446
softirqs last disabled at (3407): irq_exit+0xd1/0xe0
Link: http://lkml.kernel.org/r/20181127055429.251614-3-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com>
Cc: <stable@vger.kernel.org> [4.14+]
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.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 27b202c64c84..a46776a84480 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -366,8 +366,10 @@ static ssize_t backing_dev_store(struct device *dev, bdev = bdgrab(I_BDEV(inode)); err = blkdev_get(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL, zram); - if (err < 0) + if (err < 0) { + bdev = NULL; goto out; + } nr_pages = i_size_read(inode) >> PAGE_SHIFT; bitmap_sz = BITS_TO_LONGS(nr_pages) * sizeof(long); |