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| author | Vasiliy Kulikov <segoon@openwall.com> | 2011-06-24 16:08:38 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-08-08 10:36:08 -0700 |
| commit | 000c40644220a5cea94b46889b1be5275152f172 (patch) | |
| tree | 59085e5165e2af3cc00fafa0de14049b7ec77286 | |
| parent | 20e25df086ca0a450479bfe7c24b4f4b5b3f6dab (diff) | |
| download | lwn-000c40644220a5cea94b46889b1be5275152f172.tar.gz lwn-000c40644220a5cea94b46889b1be5275152f172.zip | |
proc: restrict access to /proc/PID/io
commit 1d1221f375c94ef961ba8574ac4f85c8870ddd51 upstream.
/proc/PID/io may be used for gathering private information. E.g. for
openssh and vsftpd daemons wchars/rchars may be used to learn the
precise password length. Restrict it to processes being able to ptrace
the target process.
ptrace_may_access() is needed to prevent keeping open file descriptor of
"io" file, executing setuid binary and gathering io information of the
setuid'ed process.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/proc/base.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 65053a1ad043..3f14afff6df0 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2519,6 +2519,9 @@ static int do_io_accounting(struct task_struct *task, char *buffer, int whole) struct task_io_accounting acct = task->ioac; unsigned long flags; + if (!ptrace_may_access(task, PTRACE_MODE_READ)) + return -EACCES; + if (whole && lock_task_sighand(task, &flags)) { struct task_struct *t = task; @@ -2641,7 +2644,7 @@ static const struct pid_entry tgid_base_stuff[] = { REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), #endif #ifdef CONFIG_TASK_IO_ACCOUNTING - INF("io", S_IRUGO, proc_tgid_io_accounting), + INF("io", S_IRUSR, proc_tgid_io_accounting), #endif }; @@ -2977,7 +2980,7 @@ static const struct pid_entry tid_base_stuff[] = { REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), #endif #ifdef CONFIG_TASK_IO_ACCOUNTING - INF("io", S_IRUGO, proc_tid_io_accounting), + INF("io", S_IRUSR, proc_tid_io_accounting), #endif }; |