diff options
author | Hugh Dickins <hughd@google.com> | 2012-10-07 20:32:51 -0700 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2012-10-30 23:26:40 +0000 |
commit | ba3385bc8c513fd741f09ef75e53e0e6547b079e (patch) | |
tree | df167ad882b09ef11b54ab95f4e0280f6323dabf | |
parent | c03970223182c35eeff66d4ff319bf2d97f4efc3 (diff) |
tmpfs,ceph,gfs2,isofs,reiserfs,xfs: fix fh_len checking
commit 35c2a7f4908d404c9124c2efc6ada4640ca4d5d5 upstream.
Fuzzing with trinity oopsed on the 1st instruction of shmem_fh_to_dentry(),
u64 inum = fid->raw[2];
which is unhelpfully reported as at the end of shmem_alloc_inode():
BUG: unable to handle kernel paging request at ffff880061cd3000
IP: [<ffffffff812190d0>] shmem_alloc_inode+0x40/0x40
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Call Trace:
[<ffffffff81488649>] ? exportfs_decode_fh+0x79/0x2d0
[<ffffffff812d77c3>] do_handle_open+0x163/0x2c0
[<ffffffff812d792c>] sys_open_by_handle_at+0xc/0x10
[<ffffffff83a5f3f8>] tracesys+0xe1/0xe6
Right, tmpfs is being stupid to access fid->raw[2] before validating that
fh_len includes it: the buffer kmalloc'ed by do_sys_name_to_handle() may
fall at the end of a page, and the next page not be present.
But some other filesystems (ceph, gfs2, isofs, reiserfs, xfs) are being
careless about fh_len too, in fh_to_dentry() and/or fh_to_parent(), and
could oops in the same way: add the missing fh_len checks to those.
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Sage Weil <sage@inktank.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r-- | fs/ceph/export.c | 18 | ||||
-rw-r--r-- | fs/gfs2/export.c | 4 | ||||
-rw-r--r-- | fs/isofs/export.c | 2 | ||||
-rw-r--r-- | fs/reiserfs/inode.c | 6 | ||||
-rw-r--r-- | fs/xfs/xfs_export.c | 3 | ||||
-rw-r--r-- | mm/shmem.c | 6 |
6 files changed, 31 insertions, 8 deletions
diff --git a/fs/ceph/export.c b/fs/ceph/export.c index 9fbcdecaaccd..b0010306b1c1 100644 --- a/fs/ceph/export.c +++ b/fs/ceph/export.c @@ -91,7 +91,7 @@ static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len, * FIXME: we should try harder by querying the mds for the ino. */ static struct dentry *__fh_to_dentry(struct super_block *sb, - struct ceph_nfs_fh *fh) + struct ceph_nfs_fh *fh, int fh_len) { struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; struct inode *inode; @@ -99,6 +99,9 @@ static struct dentry *__fh_to_dentry(struct super_block *sb, struct ceph_vino vino; int err; + if (fh_len < sizeof(*fh) / 4) + return ERR_PTR(-ESTALE); + dout("__fh_to_dentry %llx\n", fh->ino); vino.ino = fh->ino; vino.snap = CEPH_NOSNAP; @@ -142,7 +145,7 @@ static struct dentry *__fh_to_dentry(struct super_block *sb, * convert connectable fh to dentry */ static struct dentry *__cfh_to_dentry(struct super_block *sb, - struct ceph_nfs_confh *cfh) + struct ceph_nfs_confh *cfh, int fh_len) { struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; struct inode *inode; @@ -150,6 +153,9 @@ static struct dentry *__cfh_to_dentry(struct super_block *sb, struct ceph_vino vino; int err; + if (fh_len < sizeof(*cfh) / 4) + return ERR_PTR(-ESTALE); + dout("__cfh_to_dentry %llx (%llx/%x)\n", cfh->ino, cfh->parent_ino, cfh->parent_name_hash); @@ -199,9 +205,11 @@ static struct dentry *ceph_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { if (fh_type == 1) - return __fh_to_dentry(sb, (struct ceph_nfs_fh *)fid->raw); + return __fh_to_dentry(sb, (struct ceph_nfs_fh *)fid->raw, + fh_len); else - return __cfh_to_dentry(sb, (struct ceph_nfs_confh *)fid->raw); + return __cfh_to_dentry(sb, (struct ceph_nfs_confh *)fid->raw, + fh_len); } /* @@ -222,6 +230,8 @@ static struct dentry *ceph_fh_to_parent(struct super_block *sb, if (fh_type == 1) return ERR_PTR(-ESTALE); + if (fh_len < sizeof(*cfh) / 4) + return ERR_PTR(-ESTALE); pr_debug("fh_to_parent %llx/%d\n", cfh->parent_ino, cfh->parent_name_hash); diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c index fe9945f2ff72..5235d6ee28aa 100644 --- a/fs/gfs2/export.c +++ b/fs/gfs2/export.c @@ -167,6 +167,8 @@ static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid, case GFS2_SMALL_FH_SIZE: case GFS2_LARGE_FH_SIZE: case GFS2_OLD_FH_SIZE: + if (fh_len < GFS2_SMALL_FH_SIZE) + return NULL; this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32; this.no_formal_ino |= be32_to_cpu(fh[1]); this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32; @@ -186,6 +188,8 @@ static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid, switch (fh_type) { case GFS2_LARGE_FH_SIZE: case GFS2_OLD_FH_SIZE: + if (fh_len < GFS2_LARGE_FH_SIZE) + return NULL; parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32; parent.no_formal_ino |= be32_to_cpu(fh[5]); parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32; diff --git a/fs/isofs/export.c b/fs/isofs/export.c index dd4687ff30d0..516eb21895c6 100644 --- a/fs/isofs/export.c +++ b/fs/isofs/export.c @@ -179,7 +179,7 @@ static struct dentry *isofs_fh_to_parent(struct super_block *sb, { struct isofs_fid *ifid = (struct isofs_fid *)fid; - if (fh_type != 2) + if (fh_len < 2 || fh_type != 2) return NULL; return isofs_export_iget(sb, diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index 950f13af0951..5809abb44123 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -1573,8 +1573,10 @@ struct dentry *reiserfs_fh_to_dentry(struct super_block *sb, struct fid *fid, reiserfs_warning(sb, "reiserfs-13077", "nfsd/reiserfs, fhtype=%d, len=%d - odd", fh_type, fh_len); - fh_type = 5; + fh_type = fh_len; } + if (fh_len < 2) + return NULL; return reiserfs_get_dentry(sb, fid->raw[0], fid->raw[1], (fh_type == 3 || fh_type >= 5) ? fid->raw[2] : 0); @@ -1583,6 +1585,8 @@ struct dentry *reiserfs_fh_to_dentry(struct super_block *sb, struct fid *fid, struct dentry *reiserfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { + if (fh_type > fh_len) + fh_type = fh_len; if (fh_type < 4) return NULL; diff --git a/fs/xfs/xfs_export.c b/fs/xfs/xfs_export.c index 558910f5e3c0..5703fb85f6bb 100644 --- a/fs/xfs/xfs_export.c +++ b/fs/xfs/xfs_export.c @@ -195,6 +195,9 @@ xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid, struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid; struct inode *inode = NULL; + if (fh_len < xfs_fileid_length(fileid_type)) + return NULL; + switch (fileid_type) { case FILEID_INO32_GEN_PARENT: inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino, diff --git a/mm/shmem.c b/mm/shmem.c index 7a821741ec59..126ca3536232 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1962,12 +1962,14 @@ static struct dentry *shmem_fh_to_dentry(struct super_block *sb, { struct inode *inode; struct dentry *dentry = NULL; - u64 inum = fid->raw[2]; - inum = (inum << 32) | fid->raw[1]; + u64 inum; if (fh_len < 3) return NULL; + inum = fid->raw[2]; + inum = (inum << 32) | fid->raw[1]; + inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), shmem_match, fid->raw); if (inode) { |