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| author | Arturo Giusti <koredump@protonmail.com> | 2021-05-18 12:34:57 +0200 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2021-05-20 12:14:44 +0200 |
| commit | fa236c2b2d4436d9f19ee4e5d5924e90ffd7bb43 (patch) | |
| tree | c6de1817e6a65e09a1d6d5c559929a3bb906c7a7 /fs/udf | |
| parent | a149127be52fa7eaf5b3681a0317a2bbb772d5a9 (diff) | |
| download | linux-fa236c2b2d4436d9f19ee4e5d5924e90ffd7bb43.tar.gz linux-fa236c2b2d4436d9f19ee4e5d5924e90ffd7bb43.tar.xz | |
udf: Fix NULL pointer dereference in udf_symlink function
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>
Diffstat (limited to 'fs/udf')
| -rw-r--r-- | fs/udf/namei.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/udf/namei.c b/fs/udf/namei.c index 3ae9f1e91984..7c7c9bbbfa57 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -934,6 +934,10 @@ static int udf_symlink(struct user_namespace *mnt_userns, struct inode *dir, 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); |