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| author | Xinyong <xinyong.fang@linux.alibaba.com> | 2018-03-02 19:20:07 +0800 |
|---|---|---|
| committer | Felipe Balbi <felipe.balbi@linux.intel.com> | 2018-03-05 10:42:53 +0200 |
| commit | 1a087f032111a88e826877449dfb93ceb22b78b9 (patch) | |
| tree | b8e9af24efb2bc0c4b2f53af26636875e43720c1 /drivers | |
| parent | 084a804e01205bcd74cd0849bc72cb5c88f8e648 (diff) | |
| download | talos-op-linux-1a087f032111a88e826877449dfb93ceb22b78b9.tar.gz talos-op-linux-1a087f032111a88e826877449dfb93ceb22b78b9.zip | |
usb: gadget: f_fs: Fix use-after-free in ffs_fs_kill_sb()
When I debug a kernel crash issue in funcitonfs, found ffs_data.ref
overflowed, While functionfs is unmounting, ffs_data is put twice.
Commit 43938613c6fd ("drivers, usb: convert ffs_data.ref from atomic_t to
refcount_t") can avoid refcount overflow, but that is risk some situations.
So no need put ffs data in ffs_fs_kill_sb, already put in ffs_data_closed.
The issue can be reproduced in Mediatek mt6763 SoC, ffs for ADB device.
KASAN enabled configuration reports use-after-free errro.
BUG: KASAN: use-after-free in refcount_dec_and_test+0x14/0xe0 at addr ffffffc0579386a0
Read of size 4 by task umount/4650
====================================================
BUG kmalloc-512 (Tainted: P W O ): kasan: bad access detected
-----------------------------------------------------------------------------
INFO: Allocated in ffs_fs_mount+0x194/0x844 age=22856 cpu=2 pid=566
alloc_debug_processing+0x1ac/0x1e8
___slab_alloc.constprop.63+0x640/0x648
__slab_alloc.isra.57.constprop.62+0x24/0x34
kmem_cache_alloc_trace+0x1a8/0x2bc
ffs_fs_mount+0x194/0x844
mount_fs+0x6c/0x1d0
vfs_kern_mount+0x50/0x1b4
do_mount+0x258/0x1034
INFO: Freed in ffs_data_put+0x25c/0x320 age=0 cpu=3 pid=4650
free_debug_processing+0x22c/0x434
__slab_free+0x2d8/0x3a0
kfree+0x254/0x264
ffs_data_put+0x25c/0x320
ffs_data_closed+0x124/0x15c
ffs_fs_kill_sb+0xb8/0x110
deactivate_locked_super+0x6c/0x98
deactivate_super+0xb0/0xbc
INFO: Object 0xffffffc057938600 @offset=1536 fp=0x (null)
......
Call trace:
[<ffffff900808cf5c>] dump_backtrace+0x0/0x250
[<ffffff900808d3a0>] show_stack+0x14/0x1c
[<ffffff90084a8c04>] dump_stack+0xa0/0xc8
[<ffffff900826c2b4>] print_trailer+0x158/0x260
[<ffffff900826d9d8>] object_err+0x3c/0x40
[<ffffff90082745f0>] kasan_report_error+0x2a8/0x754
[<ffffff9008274f84>] kasan_report+0x5c/0x60
[<ffffff9008273208>] __asan_load4+0x70/0x88
[<ffffff90084cd81c>] refcount_dec_and_test+0x14/0xe0
[<ffffff9008d98f9c>] ffs_data_put+0x80/0x320
[<ffffff9008d9d904>] ffs_fs_kill_sb+0xc8/0x110
[<ffffff90082852a0>] deactivate_locked_super+0x6c/0x98
[<ffffff900828537c>] deactivate_super+0xb0/0xbc
[<ffffff90082af0c0>] cleanup_mnt+0x64/0xec
[<ffffff90082af1b0>] __cleanup_mnt+0x10/0x18
[<ffffff90080d9e68>] task_work_run+0xcc/0x124
[<ffffff900808c8c0>] do_notify_resume+0x60/0x70
[<ffffff90080866e4>] work_pending+0x10/0x14
Cc: stable@vger.kernel.org
Signed-off-by: Xinyong <xinyong.fang@linux.alibaba.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/gadget/function/f_fs.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index c2592d883f67..d2428a9e8900 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1538,7 +1538,6 @@ ffs_fs_kill_sb(struct super_block *sb) if (sb->s_fs_info) { ffs_release_dev(sb->s_fs_info); ffs_data_closed(sb->s_fs_info); - ffs_data_put(sb->s_fs_info); } } |
