[tip: timers/core] time/namespace: Validate nanosecond field in proc_timens_set_offset()

[tip-bot2 for Malaya Kumar Rout]

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     06aba58e58492d2b8eae059274caed29025ea96e
Gitweb:        https://git.kernel.org/tip/06aba58e58492d2b8eae059274caed29025ea96e
Author:        Malaya Kumar Rout <malayarout91@xxxxxxxxx>
AuthorDate:    Sat, 04 Jul 2026 15:04:28 +05:30
Committer:     Thomas Gleixner <tglx@xxxxxxxxxx>
CommitterDate: Tue, 07 Jul 2026 23:26:58 +02:00

time/namespace: Validate nanosecond field in proc_timens_set_offset()

The function validates tv_sec to be within [-KTIME_SEC_MAX, KTIME_SEC_MAX]
but never validates that tv_nsec is within the valid range of
[0, NSEC_PER_SEC-1] before using it in timespec64_add().

timespec64_add() expects both timespec64 structures to have normalized
values with tv_nsec in the range [0, 999999999]. If off->val.tv_nsec
contains invalid values (negative or >= NSEC_PER_SEC), it could lead to
incorrect calculations or unexpected behavior.

Add validation to ensure tv_nsec is within the valid range before
performing the addition.

Fixes: 04a8682a71be ("fs/proc: Introduce /proc/pid/timens_offsets")
Signed-off-by: Malaya Kumar Rout <malayarout91@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
Link: https://patch.msgid.link/20260704093429.89350-1-malayarout91@xxxxxxxxx
---
 kernel/time/namespace.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c
index 5fa0af6..3aff27b 100644
--- a/kernel/time/namespace.c
+++ b/kernel/time/namespace.c
@@ -293,10 +293,12 @@ int proc_timens_set_offset(struct file *file, struct task_struct *p,
 			return -EINVAL;
 		}
 
-		if (off->val.tv_sec > KTIME_SEC_MAX ||
-		    off->val.tv_sec < -KTIME_SEC_MAX)
+		if (off->val.tv_sec > KTIME_SEC_MAX || off->val.tv_sec < -KTIME_SEC_MAX)
 			return -ERANGE;
 
+		if (off->val.tv_nsec < 0 || off->val.tv_nsec >= NSEC_PER_SEC)
+			return -EINVAL;
+
 		tp = timespec64_add(tp, off->val);
 		/*
 		 * KTIME_SEC_MAX is divided by 2 to be sure that KTIME_MAX is