diff options
| author | Neil Brown <neilb@suse.de> | 2006-07-30 03:03:01 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-07-31 13:28:36 -0700 |
| commit | 2ccb48ebb4de139eef4fcefd5f2bb823cb0d81b9 (patch) | |
| tree | e06a83c7306e143175a87df2328b45e1ef34da5b | |
| parent | f712c0c7e1796f92e45e4de144e247816d974b8f (diff) | |
| download | linux-2ccb48ebb4de139eef4fcefd5f2bb823cb0d81b9.tar.gz | |
[PATCH] ext3: avoid triggering ext3_error on bad NFS file handle
The inode number out of an NFS file handle gets passed eventually to
ext3_get_inode_block() without any checking. If ext3_get_inode_block()
allows it to trigger an error, then bad filehandles can have unpleasant
effect - ext3_error() will usually cause a forced read-only remount, or a
panic if `errors=panic' was used.
So remove the call to ext3_error there and put a matching check in
ext3/namei.c where inode numbers are read off storage.
[akpm@osdl.org: fix off-by-one error]
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: <stable@kernel.org>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Eric Sandeen <esandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | fs/ext3/inode.c | 13 | ||||
| -rw-r--r-- | fs/ext3/namei.c | 15 | ||||
| -rw-r--r-- | include/linux/ext3_fs.h | 9 |
3 files changed, 29 insertions, 8 deletions
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index f804d5e9d60c6..ab034d3053ead 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -2402,14 +2402,15 @@ static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb, struct buffer_head *bh; struct ext3_group_desc * gdp; - - if ((ino != EXT3_ROOT_INO && ino != EXT3_JOURNAL_INO && - ino != EXT3_RESIZE_INO && ino < EXT3_FIRST_INO(sb)) || - ino > le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count)) { - ext3_error(sb, "ext3_get_inode_block", - "bad inode number: %lu", ino); + if (!ext3_valid_inum(sb, ino)) { + /* + * This error is already checked for in namei.c unless we are + * looking at an NFS filehandle, in which case no error + * report is needed + */ return 0; } + block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb); if (block_group >= EXT3_SB(sb)->s_groups_count) { ext3_error(sb,"ext3_get_inode_block","group >= groups count"); diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c index d9176dba36980..2aa7101b27cd3 100644 --- a/fs/ext3/namei.c +++ b/fs/ext3/namei.c @@ -1000,7 +1000,12 @@ static struct dentry *ext3_lookup(struct inode * dir, struct dentry *dentry, str if (bh) { unsigned long ino = le32_to_cpu(de->inode); brelse (bh); - inode = iget(dir->i_sb, ino); + if (!ext3_valid_inum(dir->i_sb, ino)) { + ext3_error(dir->i_sb, "ext3_lookup", + "bad inode number: %lu", ino); + inode = NULL; + } else + inode = iget(dir->i_sb, ino); if (!inode) return ERR_PTR(-EACCES); @@ -1028,7 +1033,13 @@ struct dentry *ext3_get_parent(struct dentry *child) return ERR_PTR(-ENOENT); ino = le32_to_cpu(de->inode); brelse(bh); - inode = iget(child->d_inode->i_sb, ino); + + if (!ext3_valid_inum(child->d_inode->i_sb, ino)) { + ext3_error(child->d_inode->i_sb, "ext3_get_parent", + "bad inode number: %lu", ino); + inode = NULL; + } else + inode = iget(child->d_inode->i_sb, ino); if (!inode) return ERR_PTR(-EACCES); diff --git a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h index 5607e6457a65b..9f9cce7bd86dd 100644 --- a/include/linux/ext3_fs.h +++ b/include/linux/ext3_fs.h @@ -492,6 +492,15 @@ static inline struct ext3_inode_info *EXT3_I(struct inode *inode) { return container_of(inode, struct ext3_inode_info, vfs_inode); } + +static inline int ext3_valid_inum(struct super_block *sb, unsigned long ino) +{ + return ino == EXT3_ROOT_INO || + ino == EXT3_JOURNAL_INO || + ino == EXT3_RESIZE_INO || + (ino >= EXT3_FIRST_INO(sb) && + ino <= le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count)); +} #else /* Assume that user mode programs are passing in an ext3fs superblock, not * a kernel struct super_block. This will allow us to call the feature-test |