From 0fca385d6ebc3cabb20f67bcf8a71f1448bdc001 Mon Sep 17 00:00:00 2001 From: Liu Shixin Date: Thu, 3 Nov 2022 16:33:01 +0800 Subject: [PATCH] btrfs: fix match incorrectly in dev_args_match_device syzkaller found a failed assertion: assertion failed: (args->devid != (u64)-1) || args->missing, in fs/btrfs/volumes.c:6921 This can be triggered when we set devid to (u64)-1 by ioctl. In this case, the match of devid will be skipped and the match of device may succeed incorrectly. Patch 562d7b1512f7 introduced this function which is used to match device. This function contains two matching scenarios, we can distinguish them by checking the value of args->missing rather than check whether args->devid and args->uuid is default value. Reported-by: syzbot+031687116258450f9853@syzkaller.appspotmail.com Fixes: 562d7b1512f7 ("btrfs: handle device lookup with btrfs_dev_lookup_args") CC: stable@vger.kernel.org # 5.16+ Reviewed-by: Nikolay Borisov Signed-off-by: Liu Shixin Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index a8d4bc6..f09d09c 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6918,18 +6918,18 @@ static bool dev_args_match_fs_devices(const struct btrfs_dev_lookup_args *args, static bool dev_args_match_device(const struct btrfs_dev_lookup_args *args, const struct btrfs_device *device) { - ASSERT((args->devid != (u64)-1) || args->missing); + if (args->missing) { + if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state) && + !device->bdev) + return true; + return false; + } - if ((args->devid != (u64)-1) && device->devid != args->devid) + if (device->devid != args->devid) return false; if (args->uuid && memcmp(device->uuid, args->uuid, BTRFS_UUID_SIZE) != 0) return false; - if (!args->missing) - return true; - if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state) && - !device->bdev) - return true; - return false; + return true; } /* -- 2.7.4