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authorAlexey Dobriyan <adobriyan@gmail.com>2020-12-16 07:42:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-16 09:46:15 +0300
commitc6c75deda81344c3a95d1d1f606d5cee109e5d54 (patch)
treefcb5a5a16b327e37b1a67ee6af70fc1d1518c283 /fs/proc/proc_net.c
parentfe719888344ccc7f0046e787a75bb15b6a40b39f (diff)
downloadlinux-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.c16
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;