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| 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 /fs/proc/internal.h | |
| parent | fe719888344ccc7f0046e787a75bb15b6a40b39f (diff) | |
| download | linux-c6c75deda81344c3a95d1d1f606d5cee109e5d54.tar.bz2 | |
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.h | 7 |
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; +} |