diff options
author | Vasiliy Kulikov <segoon@openwall.com> | 2011-06-24 16:08:38 +0400 |
---|---|---|
committer | Andi Kleen <ak@linux.intel.com> | 2011-08-01 13:54:59 -0700 |
commit | 658a3f90a819379393ff18d97a28b55ae8ed6328 (patch) | |
tree | 72cdfc7a203e37785d0ba3fdd9d9d2b2f4873ba4 /fs | |
parent | 2d32f62fbbad8f663c26df23242113ef9464f790 (diff) |
proc: restrict access to /proc/PID/io
[ upstream commit 1d1221f375c94ef961ba8574ac4f85c8870ddd51 ]
/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.
Said to be CVE-2011-2495
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Diffstat (limited to 'fs')
-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 d073b90f5dc6..c410e23ecd79 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2514,6 +2514,9 @@ 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; @@ -2636,7 +2639,7 @@ 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 }; @@ -2972,7 +2975,7 @@ 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 }; |