diff options
| author | Alexey Dobriyan | 2007-05-08 00:23:35 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2007-05-08 11:14:58 -0700 |
| commit | 8948e11f450e6189a79e47d6051c3d5a0b98e3f3 (patch) | |
| tree | 8cc904873cc1a8506970cf1e4a328c318a7fc4d7 /fs/proc | |
| parent | ab1b6f03a10ba1f5638188ab06bf46e33ac3a160 (diff) | |
Allow access to /proc/$PID/fd after setuid()
/proc/$PID/fd has r-x------ permissions, so if process does setuid(), it
will not be able to access /proc/*/fd/. This breaks fstatat() emulation
in glibc.
open("foo", O_RDONLY|O_DIRECTORY) = 4
setuid32(65534) = 0
stat64("/proc/self/fd/4/bar", 0xbfafb298) = -1 EACCES (Permission denied)
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Acked-By: Kirill Korotaev <dev@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/base.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index ec158dd02b3a..a721acfd4fdc 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1448,10 +1448,28 @@ static const struct file_operations proc_fd_operations = { }; /* + * /proc/pid/fd needs a special permission handler so that a process can still + * access /proc/self/fd after it has executed a setuid(). + */ +static int proc_fd_permission(struct inode *inode, int mask, + struct nameidata *nd) +{ + int rv; + + rv = generic_permission(inode, mask, NULL); + if (rv == 0) + return 0; + if (task_pid(current) == proc_pid(inode)) + rv = 0; + return rv; +} + +/* * proc directories can do almost nothing.. */ static const struct inode_operations proc_fd_inode_operations = { .lookup = proc_lookupfd, + .permission = proc_fd_permission, .setattr = proc_setattr, }; |