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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-03-15 08:36:41 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-03-15 08:36:41 +0100
commit83be46e944f630fde26ce03cb93f61a3066448e3 (patch)
treed94a48051f9311d99b615fa06adda2511f9cff2d /mm/madvise.c
parentf8096ff38d5f62d8a2c473e1bec0163a1b2b86d8 (diff)
parent1e28eed17697bcf343c6743f0028cc3b5dd88bf0 (diff)
downloadlinux-83be46e944f630fde26ce03cb93f61a3066448e3.tar.bz2
Merge v5.12-rc3 into char-misc-next
We need the char/misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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);