The sysfs buffer passed to alarms_store() is allocated with 'size + 1'
bytes and a NUL terminator is appended. However, the 'size' argument
does not account for this extra byte. The original code then allocated
'size' bytes and used strcpy() to copy 'buf', which always writes one
byte past the allocated buffer since strcpy() copies until the NUL
terminator at index 'size'.
Fix this by parsing the 'buf' parameter directly using simple_strtoll()
without allocating any intermediate memory or string copying. This
removes the overflow while simplifying the code.
Cc: stable(a)vger.kernel.org
Fixes: e2c94d6f5720 ("w1_therm: adding alarm sysfs entry")
Signed-off-by: Thorsten Blum <thorsten.blum(a)linux.dev>
---
Compile-tested only.
Changes in v4:
- Use simple_strtoll because kstrtoint also parses long long internally
- Return -ERANGE in addition to -EINVAL to match kstrtoint's behavior
- Remove any changes unrelated to fixing the buffer overflow (Krzysztof)
while maintaining the same behavior and return values as before
- Link to v3: https://lore.kernel.org/lkml/20251030155614.447905-1-thorsten.blum@linux.de…
Changes in v3:
- Add integer range check for 'temp' to match kstrtoint() behavior
- Explicitly cast 'temp' to int when calling int_to_short()
- Link to v2: https://lore.kernel.org/lkml/20251029130045.70127-2-thorsten.blum@linux.dev/
Changes in v2:
- Fix buffer overflow instead of truncating the copy using strscpy()
- Parse buffer directly using simple_strtol() as suggested by David
- Update patch subject and description
- Link to v1: https://lore.kernel.org/lkml/20251017170047.114224-2-thorsten.blum@linux.de…
---
drivers/w1/slaves/w1_therm.c | 64 ++++++++++++------------------------
1 file changed, 21 insertions(+), 43 deletions(-)
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index 9ccedb3264fb..5707fa34e804 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -1836,55 +1836,36 @@ static ssize_t alarms_store(struct device *device,
struct w1_slave *sl = dev_to_w1_slave(device);
struct therm_info info;
u8 new_config_register[3]; /* array of data to be written */
- int temp, ret;
- char *token = NULL;
+ long long temp;
+ int ret = 0;
s8 tl, th; /* 1 byte per value + temp ring order */
- char *p_args, *orig;
-
- p_args = orig = kmalloc(size, GFP_KERNEL);
- /* Safe string copys as buf is const */
- if (!p_args) {
- dev_warn(device,
- "%s: error unable to allocate memory %d\n",
- __func__, -ENOMEM);
- return size;
- }
- strcpy(p_args, buf);
-
- /* Split string using space char */
- token = strsep(&p_args, " ");
-
- if (!token) {
- dev_info(device,
- "%s: error parsing args %d\n", __func__, -EINVAL);
- goto free_m;
- }
-
- /* Convert 1st entry to int */
- ret = kstrtoint (token, 10, &temp);
+ const char *p = buf;
+ char *endp;
+
+ temp = simple_strtoll(p, &endp, 10);
+ if (p == endp || *endp != ' ')
+ ret = -EINVAL;
+ else if (temp < INT_MIN || temp > INT_MAX)
+ ret = -ERANGE;
if (ret) {
dev_info(device,
"%s: error parsing args %d\n", __func__, ret);
- goto free_m;
+ goto err;
}
tl = int_to_short(temp);
- /* Split string using space char */
- token = strsep(&p_args, " ");
- if (!token) {
- dev_info(device,
- "%s: error parsing args %d\n", __func__, -EINVAL);
- goto free_m;
- }
- /* Convert 2nd entry to int */
- ret = kstrtoint (token, 10, &temp);
+ p = endp + 1;
+ temp = simple_strtoll(p, &endp, 10);
+ if (p == endp)
+ ret = -EINVAL;
+ else if (temp < INT_MIN || temp > INT_MAX)
+ ret = -ERANGE;
if (ret) {
dev_info(device,
"%s: error parsing args %d\n", __func__, ret);
- goto free_m;
+ goto err;
}
-
/* Prepare to cast to short by eliminating out of range values */
th = int_to_short(temp);
@@ -1905,7 +1886,7 @@ static ssize_t alarms_store(struct device *device,
dev_info(device,
"%s: error reading from the slave device %d\n",
__func__, ret);
- goto free_m;
+ goto err;
}
/* Write data in the device RAM */
@@ -1913,7 +1894,7 @@ static ssize_t alarms_store(struct device *device,
dev_info(device,
"%s: Device not supported by the driver %d\n",
__func__, -ENODEV);
- goto free_m;
+ goto err;
}
ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
@@ -1922,10 +1903,7 @@ static ssize_t alarms_store(struct device *device,
"%s: error writing to the slave device %d\n",
__func__, ret);
-free_m:
- /* free allocated memory */
- kfree(orig);
-
+err:
return size;
}
--
2.51.1
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 103e17aac09cdd358133f9e00998b75d6c1f1518
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112434-arise-unlimited-9689@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 103e17aac09cdd358133f9e00998b75d6c1f1518 Mon Sep 17 00:00:00 2001
From: Sebastian Ene <sebastianene(a)google.com>
Date: Fri, 17 Oct 2025 07:57:10 +0000
Subject: [PATCH] KVM: arm64: Check the untrusted offset in FF-A memory share
Verify the offset to prevent OOB access in the hypervisor
FF-A buffer in case an untrusted large enough value
[U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX]
is set from the host kernel.
Signed-off-by: Sebastian Ene <sebastianene(a)google.com>
Acked-by: Will Deacon <will(a)kernel.org>
Link: https://patch.msgid.link/20251017075710.2605118-1-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 4e16f9b96f63..58b7d0c477d7 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -479,7 +479,7 @@ static void __do_ffa_mem_xfer(const u64 func_id,
struct ffa_mem_region_attributes *ep_mem_access;
struct ffa_composite_mem_region *reg;
struct ffa_mem_region *buf;
- u32 offset, nr_ranges;
+ u32 offset, nr_ranges, checked_offset;
int ret = 0;
if (addr_mbz || npages_mbz || fraglen > len ||
@@ -516,7 +516,12 @@ static void __do_ffa_mem_xfer(const u64 func_id,
goto out_unlock;
}
- if (fraglen < offset + sizeof(struct ffa_composite_mem_region)) {
+ if (check_add_overflow(offset, sizeof(struct ffa_composite_mem_region), &checked_offset)) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ if (fraglen < checked_offset) {
ret = FFA_RET_INVALID_PARAMETERS;
goto out_unlock;
}
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 103e17aac09cdd358133f9e00998b75d6c1f1518
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112434-impending-cupid-a11e@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 103e17aac09cdd358133f9e00998b75d6c1f1518 Mon Sep 17 00:00:00 2001
From: Sebastian Ene <sebastianene(a)google.com>
Date: Fri, 17 Oct 2025 07:57:10 +0000
Subject: [PATCH] KVM: arm64: Check the untrusted offset in FF-A memory share
Verify the offset to prevent OOB access in the hypervisor
FF-A buffer in case an untrusted large enough value
[U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX]
is set from the host kernel.
Signed-off-by: Sebastian Ene <sebastianene(a)google.com>
Acked-by: Will Deacon <will(a)kernel.org>
Link: https://patch.msgid.link/20251017075710.2605118-1-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 4e16f9b96f63..58b7d0c477d7 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -479,7 +479,7 @@ static void __do_ffa_mem_xfer(const u64 func_id,
struct ffa_mem_region_attributes *ep_mem_access;
struct ffa_composite_mem_region *reg;
struct ffa_mem_region *buf;
- u32 offset, nr_ranges;
+ u32 offset, nr_ranges, checked_offset;
int ret = 0;
if (addr_mbz || npages_mbz || fraglen > len ||
@@ -516,7 +516,12 @@ static void __do_ffa_mem_xfer(const u64 func_id,
goto out_unlock;
}
- if (fraglen < offset + sizeof(struct ffa_composite_mem_region)) {
+ if (check_add_overflow(offset, sizeof(struct ffa_composite_mem_region), &checked_offset)) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ if (fraglen < checked_offset) {
ret = FFA_RET_INVALID_PARAMETERS;
goto out_unlock;
}
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 103e17aac09cdd358133f9e00998b75d6c1f1518
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112430-brunch-scone-7ffb@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 103e17aac09cdd358133f9e00998b75d6c1f1518 Mon Sep 17 00:00:00 2001
From: Sebastian Ene <sebastianene(a)google.com>
Date: Fri, 17 Oct 2025 07:57:10 +0000
Subject: [PATCH] KVM: arm64: Check the untrusted offset in FF-A memory share
Verify the offset to prevent OOB access in the hypervisor
FF-A buffer in case an untrusted large enough value
[U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX]
is set from the host kernel.
Signed-off-by: Sebastian Ene <sebastianene(a)google.com>
Acked-by: Will Deacon <will(a)kernel.org>
Link: https://patch.msgid.link/20251017075710.2605118-1-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 4e16f9b96f63..58b7d0c477d7 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -479,7 +479,7 @@ static void __do_ffa_mem_xfer(const u64 func_id,
struct ffa_mem_region_attributes *ep_mem_access;
struct ffa_composite_mem_region *reg;
struct ffa_mem_region *buf;
- u32 offset, nr_ranges;
+ u32 offset, nr_ranges, checked_offset;
int ret = 0;
if (addr_mbz || npages_mbz || fraglen > len ||
@@ -516,7 +516,12 @@ static void __do_ffa_mem_xfer(const u64 func_id,
goto out_unlock;
}
- if (fraglen < offset + sizeof(struct ffa_composite_mem_region)) {
+ if (check_add_overflow(offset, sizeof(struct ffa_composite_mem_region), &checked_offset)) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ if (fraglen < checked_offset) {
ret = FFA_RET_INVALID_PARAMETERS;
goto out_unlock;
}
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 103e17aac09cdd358133f9e00998b75d6c1f1518
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112430-imperial-yearling-e395@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 103e17aac09cdd358133f9e00998b75d6c1f1518 Mon Sep 17 00:00:00 2001
From: Sebastian Ene <sebastianene(a)google.com>
Date: Fri, 17 Oct 2025 07:57:10 +0000
Subject: [PATCH] KVM: arm64: Check the untrusted offset in FF-A memory share
Verify the offset to prevent OOB access in the hypervisor
FF-A buffer in case an untrusted large enough value
[U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX]
is set from the host kernel.
Signed-off-by: Sebastian Ene <sebastianene(a)google.com>
Acked-by: Will Deacon <will(a)kernel.org>
Link: https://patch.msgid.link/20251017075710.2605118-1-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 4e16f9b96f63..58b7d0c477d7 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -479,7 +479,7 @@ static void __do_ffa_mem_xfer(const u64 func_id,
struct ffa_mem_region_attributes *ep_mem_access;
struct ffa_composite_mem_region *reg;
struct ffa_mem_region *buf;
- u32 offset, nr_ranges;
+ u32 offset, nr_ranges, checked_offset;
int ret = 0;
if (addr_mbz || npages_mbz || fraglen > len ||
@@ -516,7 +516,12 @@ static void __do_ffa_mem_xfer(const u64 func_id,
goto out_unlock;
}
- if (fraglen < offset + sizeof(struct ffa_composite_mem_region)) {
+ if (check_add_overflow(offset, sizeof(struct ffa_composite_mem_region), &checked_offset)) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ if (fraglen < checked_offset) {
ret = FFA_RET_INVALID_PARAMETERS;
goto out_unlock;
}
Make sure to drop the reference taken when looking up the companion
device during probe().
Note that holding a reference to a device does not prevent its driver
data from going away so there is no point in keeping the reference.
Fixes: f68ba6912bd2 ("drm/tegra: dc: Link DC1 to DC0 on Tegra20")
Cc: stable(a)vger.kernel.org # 4.16
Cc: Dmitry Osipenko <digetx(a)gmail.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/gpu/drm/tegra/dc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 59d5c1ba145a..7a6b30df6a89 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -3148,6 +3148,8 @@ static int tegra_dc_couple(struct tegra_dc *dc)
dc->client.parent = &parent->client;
dev_dbg(dc->dev, "coupled to %s\n", dev_name(companion));
+
+ put_device(companion);
}
return 0;
--
2.51.2