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Vegard Nossum authored
commit f70749ca upstream. An extent with lblock = 4294967295 and len = 1 will pass the ext4_valid_extent() test: ext4_lblk_t last = lblock + len - 1; if (len == 0 || lblock > last) return 0; since last = 4294967295 + 1 - 1 = 4294967295. This would later trigger the BUG_ON(es->es_lblk + es->es_len < es->es_lblk) in ext4_es_end(). We can simplify it by removing the - 1 altogether and changing the test to use lblock + len <= lblock, since now if len = 0, then lblock + 0 == lblock and it fails, and if len > 0 then lblock + len > lblock in order to pass (i.e. it doesn't overflow). Fixes: 5946d089 ("ext4: check for overlapping extents in ext4_valid_extent_entries()") Fixes: 2f974865 ("ext4: check for zero length extent explicitly") Cc: Eryu Guan <guaneryu@gmail.com> Signed-off-by:
Phil Turnbull <phil.turnbull@oracle.com> Signed-off-by:
Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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