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authorDavid S. Miller <davem@davemloft.net>2021-03-26 01:31:22 +0300
committerDavid S. Miller <davem@davemloft.net>2021-03-26 01:31:22 +0300
commitefd13b71a3fa31413f8d15342e01d44b60b0a432 (patch)
tree2ed1b299e25538c5a60485a1047507b49d3e0ecf /mm/madvise.c
parent84c7f6c33f42a12eb036ebf0f0e3670799304120 (diff)
parent002322402dafd846c424ffa9240a937f49b48c42 (diff)
downloadlinux-efd13b71a3fa31413f8d15342e01d44b60b0a432.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'mm/madvise.c')
-rw-r--r--mm/madvise.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/mm/madvise.c b/mm/madvise.c
index df692d2e35d4..01fef79ac761 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1198,12 +1198,22 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec,
goto release_task;
}
- mm = mm_access(task, PTRACE_MODE_ATTACH_FSCREDS);
+ /* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */
+ mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
if (IS_ERR_OR_NULL(mm)) {
ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH;
goto release_task;
}
+ /*
+ * Require CAP_SYS_NICE for influencing process performance. Note that
+ * only non-destructive hints are currently supported.
+ */
+ if (!capable(CAP_SYS_NICE)) {
+ ret = -EPERM;
+ goto release_mm;
+ }
+
total_len = iov_iter_count(&iter);
while (iov_iter_count(&iter)) {
@@ -1218,6 +1228,7 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec,
if (ret == 0)
ret = total_len - iov_iter_count(&iter);
+release_mm:
mmput(mm);
release_task:
put_task_struct(task);