[PATCH AUTOSEL 5.10 1/3] printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX

[PATCH AUTOSEL 5.10 1/3] printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX

[Sasha Levin]

From: Kuan-Wei Chiu <visitorckw@gmail.com>

[ Upstream commit 3d6f83df8ff2d5de84b50377e4f0d45e25311c7a ]

Shifting 1 << 31 on a 32-bit int causes signed integer overflow, which
leads to undefined behavior. To prevent this, cast 1 to u32 before
performing the shift, ensuring well-defined behavior.

This change explicitly avoids any potential overflow by ensuring that
the shift occurs on an unsigned 32-bit integer.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240928113608.1438087-1-visitorckw@gmail.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/printk/printk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index a8af93cbc2936..3a7fd61c0e7be 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -420,7 +420,7 @@ static u64 clear_seq;
 /* record buffer */
 #define LOG_ALIGN __alignof__(unsigned long)
 #define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
-#define LOG_BUF_LEN_MAX (u32)(1 << 31)
+#define LOG_BUF_LEN_MAX ((u32)1 << 31)
 static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
 static char *log_buf = __log_buf;
 static u32 log_buf_len = __LOG_BUF_LEN;
-- 
2.39.5

[PATCH AUTOSEL 5.10 2/3] drm/sti: hdmi: use eld_mutex to protect access to connector->eld

[Sasha Levin]

From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

[ Upstream commit e99c0b517bcd53cf61f998a3c4291333401cb391 ]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Raphael Gallais-Pou <rgallaispou@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241206-drm-connector-eld-mutex-v2-9-c9bce1ee8bea@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/sti/sti_hdmi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
index 1bcee73f51144..f5dd2aca097a7 100644
--- a/drivers/gpu/drm/sti/sti_hdmi.c
+++ b/drivers/gpu/drm/sti/sti_hdmi.c
@@ -1213,7 +1213,9 @@ static int hdmi_audio_get_eld(struct device *dev, void *data, uint8_t *buf, size
 	struct drm_connector *connector = hdmi->drm_connector;
 
 	DRM_DEBUG_DRIVER("\n");
+	mutex_lock(&connector->eld_mutex);
 	memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
+	mutex_unlock(&connector->eld_mutex);
 
 	return 0;
 }
-- 
2.39.5

[PATCH AUTOSEL 5.10 3/3] safesetid: check size of policy writes

[Sasha Levin]

From: Leo Stone <leocstone@gmail.com>

[ Upstream commit f09ff307c7299392f1c88f763299e24bc99811c7 ]

syzbot attempts to write a buffer with a large size to a sysfs entry
with writes handled by handle_policy_update(), triggering a warning
in kmalloc.

Check the size specified for write buffers before allocating.

Reported-by: syzbot+4eb7a741b3216020043a@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4eb7a741b3216020043a
Signed-off-by: Leo Stone <leocstone@gmail.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/safesetid/securityfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/security/safesetid/securityfs.c b/security/safesetid/securityfs.c
index 25310468bcddf..8e1ffd70b18ab 100644
--- a/security/safesetid/securityfs.c
+++ b/security/safesetid/securityfs.c
@@ -143,6 +143,9 @@ static ssize_t handle_policy_update(struct file *file,
 	char *buf, *p, *end;
 	int err;
 
+	if (len >= KMALLOC_MAX_SIZE)
+		return -EINVAL;
+
 	pol = kmalloc(sizeof(struct setid_ruleset), GFP_KERNEL);
 	if (!pol)
 		return -ENOMEM;
-- 
2.39.5