6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: I Viswanath [ Upstream commit e9f35294e18da82162004a2f35976e7031aaf7f9 ] syzbot reported WARNING in max_vclocks_store. This occurs when the argument max is too large for kcalloc to handle. Extend the guard to guard against values that are too large for kcalloc Reported-by: syzbot+94d20db923b9f51be0df@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=94d20db923b9f51be0df Tested-by: syzbot+94d20db923b9f51be0df@syzkaller.appspotmail.com Fixes: 73f37068d540 ("ptp: support ptp physical/virtual clocks conversion") Signed-off-by: I Viswanath Acked-by: Richard Cochran Link: https://patch.msgid.link/20250925155908.5034-1-viswanathiyyappan@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/ptp/ptp_private.h | 1 + drivers/ptp/ptp_sysfs.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h index baf05d55376dd..855dddee694f5 100644 --- a/drivers/ptp/ptp_private.h +++ b/drivers/ptp/ptp_private.h @@ -20,6 +20,7 @@ #define PTP_MAX_TIMESTAMPS 128 #define PTP_BUF_TIMESTAMPS 30 #define PTP_DEFAULT_MAX_VCLOCKS 20 +#define PTP_MAX_VCLOCKS_LIMIT (KMALLOC_MAX_SIZE/(sizeof(int))) enum { PTP_LOCK_PHYSICAL = 0, diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c index 952d3e968bdf9..d975531f290d8 100644 --- a/drivers/ptp/ptp_sysfs.c +++ b/drivers/ptp/ptp_sysfs.c @@ -286,7 +286,7 @@ static ssize_t max_vclocks_store(struct device *dev, size_t size; u32 max; - if (kstrtou32(buf, 0, &max) || max == 0) + if (kstrtou32(buf, 0, &max) || max == 0 || max > PTP_MAX_VCLOCKS_LIMIT) return -EINVAL; if (max == ptp->max_vclocks) -- 2.53.0