From: Gwendal Grignou gwendal@chromium.org

stable inclusion from stable-v6.6.66 commit 0069928727c2e95ca26c738fbe6e4b241aeaaf08 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEAOG CVE: CVE-2024-56622

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit eb48e9fc0028bed94a40a9352d065909f19e333c upstream.

Prevent a division by 0 when monitoring is not enabled.

Fixes: 1d8613a23f3c ("scsi: ufs: core: Introduce HBA performance monitor sysfs nodes") Cc: stable@vger.kernel.org Signed-off-by: Gwendal Grignou gwendal@chromium.org Link: https://lore.kernel.org/r/20241120062522.917157-1-gwendal@chromium.org Reviewed-by: Can Guo quic_cang@quicinc.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Heyuan Wang wangheyuan2@h-partners.com --- drivers/ufs/core/ufs-sysfs.c | 6 ++++++ 1 file changed, 6 insertions(+)

diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c index c95906443d5f..3692b39b35e7 100644 --- a/drivers/ufs/core/ufs-sysfs.c +++ b/drivers/ufs/core/ufs-sysfs.c @@ -485,6 +485,9 @@ static ssize_t read_req_latency_avg_show(struct device *dev, struct ufs_hba *hba = dev_get_drvdata(dev); struct ufs_hba_monitor *m = &hba->monitor;

+ if (!m->nr_req[READ]) + return sysfs_emit(buf, "0\n"); + return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[READ]), m->nr_req[READ])); } @@ -552,6 +555,9 @@ static ssize_t write_req_latency_avg_show(struct device *dev, struct ufs_hba *hba = dev_get_drvdata(dev); struct ufs_hba_monitor *m = &hba->monitor;

+ if (!m->nr_req[WRITE]) + return sysfs_emit(buf, "0\n"); + return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[WRITE]), m->nr_req[WRITE])); }