From: Juntong Deng juntong.deng@outlook.com
stable inclusion from stable-v5.10.202 commit 524b4f203afcf87accfe387e846f33f916f0c907 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RFEZ CVE: CVE-2023-52810
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 525b861a008143048535011f3816d407940f4bfa ]
l2nbperpage is log2(number of blks per page), and the minimum legal value should be 0, not negative.
In the case of l2nbperpage being negative, an error will occur when subsequently used as shift exponent.
Syzbot reported this bug:
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:799:12 shift exponent -16777216 is negative
Reported-by: syzbot+debee9ab7ae2b34b0307@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=debee9ab7ae2b34b0307 Signed-off-by: Juntong Deng juntong.deng@outlook.com Signed-off-by: Dave Kleikamp dave.kleikamp@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: sanglipeng sanglipeng1@jd.com Signed-off-by: Li Nan linan122@huawei.com --- fs/jfs/jfs_dmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index 0eb2d9ec912a..d1df9713ad58 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -180,7 +180,8 @@ int dbMount(struct inode *ipbmap) bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree);
bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage); - if (bmp->db_l2nbperpage > L2PSIZE - L2MINBLOCKSIZE) { + if (bmp->db_l2nbperpage > L2PSIZE - L2MINBLOCKSIZE || + bmp->db_l2nbperpage < 0) { err = -EINVAL; goto err_release_metapage; }