diff options
| author | Dongliang Mu <mudongliangabcd@gmail.com> | 2022-10-18 08:48:07 -0500 |
|---|---|---|
| committer | Dave Kleikamp <dave.kleikamp@oracle.com> | 2022-10-18 08:49:42 -0500 |
| commit | 898f706695682b9954f280d95e49fa86ffa55d08 (patch) | |
| tree | abd223efffb99bcf200b2fafa0a9282fe34f51c8 /fs/jfs | |
| parent | bbb8ceb5e2421184db9560e9d2cfaf858e1db616 (diff) | |
fs: jfs: fix shift-out-of-bounds in dbAllocAG
Syzbot found a crash : UBSAN: shift-out-of-bounds in dbAllocAG. The
underlying bug is the missing check of bmp->db_agl2size. The field can
be greater than 64 and trigger the shift-out-of-bounds.
Fix this bug by adding a check of bmp->db_agl2size in dbMount since this
field is used in many following functions. The upper bound for this
field is L2MAXL2SIZE - L2MAXAG, thanks for the help of Dave Kleikamp.
Note that, for maintenance, I reorganized error handling code of dbMount.
Reported-by: syzbot+15342c1aa6a00fb7a438@syzkaller.appspotmail.com
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Diffstat (limited to 'fs/jfs')
| -rw-r--r-- | fs/jfs/jfs_dmap.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index 6b838d3ae7c2..e1cbfbb60303 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -155,7 +155,7 @@ int dbMount(struct inode *ipbmap) struct bmap *bmp; struct dbmap_disk *dbmp_le; struct metapage *mp; - int i; + int i, err; /* * allocate/initialize the in-memory bmap descriptor @@ -170,8 +170,8 @@ int dbMount(struct inode *ipbmap) BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, PSIZE, 0); if (mp == NULL) { - kfree(bmp); - return -EIO; + err = -EIO; + goto err_kfree_bmp; } /* copy the on-disk bmap descriptor to its in-memory version. */ @@ -181,9 +181,8 @@ int dbMount(struct inode *ipbmap) bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage); bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag); if (!bmp->db_numag) { - release_metapage(mp); - kfree(bmp); - return -EINVAL; + err = -EINVAL; + goto err_release_metapage; } bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel); @@ -194,6 +193,11 @@ int dbMount(struct inode *ipbmap) bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); 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) { + err = -EINVAL; + goto err_release_metapage; + } + for (i = 0; i < MAXAG; i++) bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]); bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize); @@ -214,6 +218,12 @@ int dbMount(struct inode *ipbmap) BMAP_LOCK_INIT(bmp); return (0); + +err_release_metapage: + release_metapage(mp); +err_kfree_bmp: + kfree(bmp); + return err; } |