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| author | Alexey Gladkov <gladkov.alexey@gmail.com> | 2020-05-18 20:07:38 +0200 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-05-19 14:07:50 +0200 |
| commit | 9d78edeaec759f997c303f286ecd39daee166f2a (patch) | |
| tree | 2325279bb24196709e59a506cbf4f346c1e69a2b /security | |
| parent | posix-cpu-timers: Use pids not tasks in lookup (diff) | |
| download | linux-9d78edeaec759f997c303f286ecd39daee166f2a.tar.xz linux-9d78edeaec759f997c303f286ecd39daee166f2a.zip | |
proc: proc_pid_ns takes super_block as an argument
syzbot found that
touch /proc/testfile
causes NULL pointer dereference at tomoyo_get_local_path()
because inode of the dentry is NULL.
Before c59f415a7cb6, Tomoyo received pid_ns from proc's s_fs_info
directly. Since proc_pid_ns() can only work with inode, using it in
the tomoyo_get_local_path() was wrong.
To avoid creating more functions for getting proc_ns, change the
argument type of the proc_pid_ns() function. Then, Tomoyo can use
the existing super_block to get pid_ns.
Link: https://lkml.kernel.org/r/0000000000002f0c7505a5b0e04c@google.com
Link: https://lkml.kernel.org/r/20200518180738.2939611-1-gladkov.alexey@gmail.com
Reported-by: syzbot+c1af344512918c61362c@syzkaller.appspotmail.com
Fixes: c59f415a7cb6 ("Use proc_pid_ns() to get pid_namespace from the proc superblock")
Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/tomoyo/realpath.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c index 08b096e2f7e3..df4798980416 100644 --- a/security/tomoyo/realpath.c +++ b/security/tomoyo/realpath.c @@ -162,7 +162,7 @@ static char *tomoyo_get_local_path(struct dentry *dentry, char * const buffer, if (sb->s_magic == PROC_SUPER_MAGIC && *pos == '/') { char *ep; const pid_t pid = (pid_t) simple_strtoul(pos + 1, &ep, 10); - struct pid_namespace *proc_pidns = proc_pid_ns(d_inode(dentry)); + struct pid_namespace *proc_pidns = proc_pid_ns(sb); if (*ep == '/' && pid && pid == task_tgid_nr_ns(current, proc_pidns)) { |