diff options
| author | Alexey Dobriyan <adobriyan@gmail.com> | 2020-12-16 07:42:39 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-16 09:46:15 +0300 |
| commit | c6c75deda81344c3a95d1d1f606d5cee109e5d54 (patch) | |
| tree | fcb5a5a16b327e37b1a67ee6af70fc1d1518c283 /fs/proc/proc_net.c | |
| parent | fe719888344ccc7f0046e787a75bb15b6a40b39f (diff) | |
| download | linux-c6c75deda81344c3a95d1d1f606d5cee109e5d54.tar.xz | |
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 'fs/proc/proc_net.c')
| -rw-r--r-- | fs/proc/proc_net.c | 16 |
1 files changed, 0 insertions, 16 deletions
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c index 45c7318a2ce5..18601042af99 100644 --- a/fs/proc/proc_net.c +++ b/fs/proc/proc_net.c @@ -39,22 +39,6 @@ static struct net *get_proc_net(const struct inode *inode) return maybe_get_net(PDE_NET(PDE(inode))); } -static int proc_net_d_revalidate(struct dentry *dentry, unsigned int flags) -{ - return 0; -} - -static const struct dentry_operations proc_net_dentry_ops = { - .d_revalidate = proc_net_d_revalidate, - .d_delete = always_delete_dentry, -}; - -static void pde_force_lookup(struct proc_dir_entry *pde) -{ - /* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */ - pde->proc_dops = &proc_net_dentry_ops; -} - static int seq_open_net(struct inode *inode, struct file *file) { unsigned int state_size = PDE(inode)->state_size; |