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Qu Wenruo authored
[BUG] For fuzzed image whose DEV_ITEM has invalid total_bytes as 0, then kernel will just panic: BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 #PF error: [normal kernel read fault] PGD 800000022b2bd067 P4D 800000022b2bd067 PUD 22b2bc067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 1106 Comm: mount Not tainted 5.0.0-rc8+ #9 RIP: 0010:btrfs_verify_dev_extents+0x2a5/0x5a0 Call Trace: open_ctree+0x160d/0x2149 btrfs_mount_root+0x5b2/0x680 [CAUSE] If device extent verification finds a deivce with 0 total_bytes, then it assumes it's a seed dummy, then search for seed devices. But in this case, there is no seed device at all, causing NULL pointer. [FIX] Since this is caused by fuzzed image, let's go the tree-check way, just add a new verification for device item. Reported-by:
Yoon Jungyeon <jungyeon@gatech.edu> Link: https://bugzilla.kernel.org/show_bug.cgi?id=202691Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Signed-off-by:
Qu Wenruo <wqu@suse.com> Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:
David Sterba <dsterba@suse.com>
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