diff options
| author | Alexey Dobriyan <adobriyan@gmail.com> | 2020-12-15 20:42:39 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 22:46:15 -0800 |
| commit | c6c75deda81344c3a95d1d1f606d5cee109e5d54 (patch) | |
| tree | fcb5a5a16b327e37b1a67ee6af70fc1d1518c283 /include/linux/proc_fs.h | |
| parent | fe719888344ccc7f0046e787a75bb15b6a40b39f (diff) | |
proc: fix lookup in /proc/net subdirectories after setns(2)
Commit 1fde6f21d90f ("proc: fix /proc/net/* after setns(2)") only forced
revalidation of regular files under /proc/net/
However, /proc/net/ is unusual in the sense of /proc/net/foo handlers
take netns pointer from parent directory which is old netns.
Steps to reproduce:
(void)open("/proc/net/sctp/snmp", O_RDONLY);
unshare(CLONE_NEWNET);
int fd = open("/proc/net/sctp/snmp", O_RDONLY);
read(fd, &c, 1);
Read will read wrong data from original netns.
Patch forces lookup on every directory under /proc/net .
Link: https://lkml.kernel.org/r/20201205160916.GA109739@localhost.localdomain
Fixes: 1da4d377f943 ("proc: revalidate misc dentries")
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" <tommi.t.rantala@nokia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/proc_fs.h')
| -rw-r--r-- | include/linux/proc_fs.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 270cab43ca3d..000cc0533c33 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -80,6 +80,7 @@ extern void proc_flush_pid(struct pid *); extern struct proc_dir_entry *proc_symlink(const char *, struct proc_dir_entry *, const char *); +struct proc_dir_entry *_proc_mkdir(const char *, umode_t, struct proc_dir_entry *, void *, bool); extern struct proc_dir_entry *proc_mkdir(const char *, struct proc_dir_entry *); extern struct proc_dir_entry *proc_mkdir_data(const char *, umode_t, struct proc_dir_entry *, void *); @@ -162,6 +163,11 @@ static inline struct proc_dir_entry *proc_symlink(const char *name, static inline struct proc_dir_entry *proc_mkdir(const char *name, struct proc_dir_entry *parent) {return NULL;} static inline struct proc_dir_entry *proc_create_mount_point(const char *name) { return NULL; } +static inline struct proc_dir_entry *_proc_mkdir(const char *name, umode_t mode, + struct proc_dir_entry *parent, void *data, bool force_lookup) +{ + return NULL; +} static inline struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode, struct proc_dir_entry *parent, void *data) { return NULL; } static inline struct proc_dir_entry *proc_mkdir_mode(const char *name, @@ -199,7 +205,7 @@ struct net; static inline struct proc_dir_entry *proc_net_mkdir( struct net *net, const char *name, struct proc_dir_entry *parent) { - return proc_mkdir_data(name, 0, parent, net); + return _proc_mkdir(name, 0, parent, net, true); } struct ns_common; |