diff options
| 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 /fs/proc/base.c | |
| 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 'fs/proc/base.c')
| -rw-r--r-- | fs/proc/base.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 5a307b3bb2d1..30c9fceca0b7 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -754,7 +754,7 @@ static const struct inode_operations proc_def_inode_operations = { static int proc_single_show(struct seq_file *m, void *v) { struct inode *inode = m->private; - struct pid_namespace *ns = proc_pid_ns(inode); + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); struct pid *pid = proc_pid(inode); struct task_struct *task; int ret; @@ -1423,7 +1423,7 @@ static const struct file_operations proc_fail_nth_operations = { static int sched_show(struct seq_file *m, void *v) { struct inode *inode = m->private; - struct pid_namespace *ns = proc_pid_ns(inode); + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); struct task_struct *p; p = get_proc_task(inode); @@ -2466,7 +2466,7 @@ static int proc_timers_open(struct inode *inode, struct file *file) return -ENOMEM; tp->pid = proc_pid(inode); - tp->ns = proc_pid_ns(inode); + tp->ns = proc_pid_ns(inode->i_sb); return 0; } @@ -3377,7 +3377,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) { struct tgid_iter iter; struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb); - struct pid_namespace *ns = proc_pid_ns(file_inode(file)); + struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb); loff_t pos = ctx->pos; if (pos >= PID_MAX_LIMIT + TGID_OFFSET) @@ -3730,7 +3730,7 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx) /* f_version caches the tgid value that the last readdir call couldn't * return. lseek aka telldir automagically resets f_version to 0. */ - ns = proc_pid_ns(inode); + ns = proc_pid_ns(inode->i_sb); tid = (int)file->f_version; file->f_version = 0; for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); |