Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 239/421] udf: Fix NULL pointer dereference in udf_symlink function | Date | Mon, 19 Jul 2021 16:50:50 +0200 |
| |
From: Arturo Giusti <koredump@protonmail.com>
[ Upstream commit fa236c2b2d4436d9f19ee4e5d5924e90ffd7bb43 ]
In function udf_symlink, epos.bh is assigned with the value returned by udf_tgetblk. The function udf_tgetblk is defined in udf/misc.c and returns the value of sb_getblk function that could be NULL. Then, epos.bh is used without any check, causing a possible NULL pointer dereference when sb_getblk fails.
This fix adds a check to validate the value of epos.bh.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=213083 Signed-off-by: Arturo Giusti <koredump@protonmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org> --- fs/udf/namei.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/udf/namei.c b/fs/udf/namei.c index 58cc2414992b..9cfb555db1ad 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -948,6 +948,10 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry, iinfo->i_location.partitionReferenceNum, 0); epos.bh = udf_tgetblk(sb, block); + if (unlikely(!epos.bh)) { + err = -ENOMEM; + goto out_no_entry; + } lock_buffer(epos.bh); memset(epos.bh->b_data, 0x00, bsize); set_buffer_uptodate(epos.bh); -- 2.30.2
| |