5.4-stable review patch. If anyone has any objections, please let me know.
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From: Edward Adam Davis eadavis@qq.com
[ Upstream commit ddf2846f22e8575d6b4b6a66f2100f168b8cd73d ]
The width in dmapctl of the AG is zero, it trigger a divide error when calculating the control page level in dbAllocAG.
To avoid this issue, add a check for agwidth in dbAllocAG.
Reported-and-tested-by: syzbot+7c808908291a569281a9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7c808908291a569281a9 Signed-off-by: Edward Adam Davis eadavis@qq.com Signed-off-by: Dave Kleikamp dave.kleikamp@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/jfs/jfs_dmap.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index d4e26744b2005..d161bbafe77f6 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -204,6 +204,10 @@ int dbMount(struct inode *ipbmap) bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel); bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight); bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); + if (!bmp->db_agwidth) { + err = -EINVAL; + goto err_release_metapage; + } bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart); bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size); if (bmp->db_agl2size > L2MAXL2SIZE - L2MAXAG ||