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53a0249d68
[ Upstream commit 557c024ca7 ]
A fuzzer test introduced corruption that ends up with a depth of 0 in
dir_e_read(), causing an undefined shift by 32 at:
index = hash >> (32 - dip->i_depth);
As calculated in an open-coded way in dir_make_exhash(), the minimum
depth for an exhash directory is ilog2(sdp->sd_hash_ptrs) and 0 is
invalid as sdp->sd_hash_ptrs is fixed as sdp->bsize / 16 at mount time.
So we can avoid the undefined behaviour by checking for depth values
lower than the minimum in gfs2_dinode_in(). Values greater than the
maximum are already being checked for there.
Also switch the calculation in dir_make_exhash() to use ilog2() to
clarify how the depth is calculated.
Tested with the syzkaller repro.c and xfstests '-g quick'.
Reported-by: syzbot+4708579bb230a0582a57@syzkaller.appspotmail.com
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2189 lines
52 KiB
2189 lines
52 KiB