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authorAlexey Dobriyan <adobriyan@gmail.com>2020-12-15 20:42:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-15 22:46:15 -0800
commitc6c75deda81344c3a95d1d1f606d5cee109e5d54 (patch)
treefcb5a5a16b327e37b1a67ee6af70fc1d1518c283 /fs/proc/internal.h
parentfe719888344ccc7f0046e787a75bb15b6a40b39f (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 'fs/proc/internal.h')
-rw-r--r--fs/proc/internal.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 917cc85e3466..afbe96b6bf77 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -310,3 +310,10 @@ extern unsigned long task_statm(struct mm_struct *,
unsigned long *, unsigned long *,
unsigned long *, unsigned long *);
extern void task_mem(struct seq_file *, struct mm_struct *);
+
+extern const struct dentry_operations proc_net_dentry_ops;
+static inline 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;
+}