git: 1579b320f1a4 - main - linux(4): Zero out high order bits of nanoseconds in the compat mode.

The branch main has been updated by dchagin:

URL: https://cgit.FreeBSD.org/src/commit/?id=1579b320f1a4d555250b82fa74a391d963e7ae13

commit 1579b320f1a4d555250b82fa74a391d963e7ae13
Author:     Dmitry Chagin <dchagin@FreeBSD.org>
AuthorDate: 2022-05-08 12:38:19 +0000
Commit:     Dmitry Chagin <dchagin@FreeBSD.org>
CommitDate: 2022-05-08 12:38:19 +0000

    linux(4): Zero out high order bits of nanoseconds in the compat mode.
    
    Assuming the kernel would use random data, the 64-bit Linux kernel ignores
    upper 32 bits of tv_nsec of struct timespec64 for 32-bit binaries.
    
    MFC after:              2 weeks
---
 sys/compat/linux/linux_misc.c | 3 +++
 sys/compat/linux/linux_time.c | 8 +++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/sys/compat/linux/linux_misc.c b/sys/compat/linux/linux_misc.c
index 10f4f52ba500..81002540633e 100644
--- a/sys/compat/linux/linux_misc.c
+++ b/sys/compat/linux/linux_misc.c
@@ -910,6 +910,9 @@ static int
 linux_utimensat_lts64_to_ts(struct l_timespec64 *l_times, struct timespec *times)
 {
 
+	/* Zero out the padding in compat mode. */
+	l_times->tv_nsec &= 0xFFFFFFFFUL;
+
 	if (l_times->tv_nsec != LINUX_UTIME_OMIT &&
 	    l_times->tv_nsec != LINUX_UTIME_NOW &&
 	    (l_times->tv_nsec < 0 || l_times->tv_nsec > 999999999))
diff --git a/sys/compat/linux/linux_time.c b/sys/compat/linux/linux_time.c
index e97a1145d31b..d4f502eee7c6 100644
--- a/sys/compat/linux/linux_time.c
+++ b/sys/compat/linux/linux_time.c
@@ -177,10 +177,12 @@ int
 linux_to_native_timespec64(struct timespec *ntp, struct l_timespec64 *ltp64)
 {
 
-	if (!timespecvalid_interval(ltp64))
-		return (EINVAL);
+	/* Zero out the padding in compat mode. */
+	ntp->tv_nsec = ltp64->tv_nsec & 0xFFFFFFFFUL;
 	ntp->tv_sec = ltp64->tv_sec;
-	ntp->tv_nsec = ltp64->tv_nsec;
+
+	if (!timespecvalid_interval(ntp))
+		return (EINVAL);
 
 	return (0);
 }