ext4: fix data races when using cached status extents
commit 492888df upstream. When using cached extent stored in extent status tree in tree->cache_es another process holding ei->i_es_lock for reading can be racing with us setting new value of tree->cache_es. If the compiler would decide to refetch tree->cache_es at an unfortunate moment, it could result in a bogus in_range() check. Fix the possible race by using READ_ONCE() when using tree->cache_es only under ei->i_es_lock for reading. Cc: stable@kernel.org Reported-by:<syzbot+4a03518df1e31b537066@syzkaller.appspotmail.com> Link: https://lore.kernel.org/all/000000000000d3b33905fa0fd4a6@google.com Suggested-by:
Dmitry Vyukov <dvyukov@google.com> Signed-off-by:
Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230504125524.10802-1-jack@suse.cz Signed-off-by:
Theodore Ts'o <tytso@mit.edu> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
be7b6374
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