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| author | Syed Labeeq Sajid Bukhari <syedlabeeq@gmail.com> | 2026-09-10 19:03:43 +0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-09-10 17:08:52 +0200 |
| commit | 8a0200d14acd9db388b85cd016e68a4e60d900ec (patch) | |
| tree | 673be79a53110c6c37c5514aa874854e13677c42 | |
| parent | 90156585765b29304f07b0e4a1c56a969876fcfc (diff) | |
| download | linux-next-8a0200d14acd9db388b85cd016e68a4e60d900ec.tar.gz linux-next-8a0200d14acd9db388b85cd016e68a4e60d900ec.zip | |
usb: storage: sierra_ms: reject short SWoC info transfers
sierra_get_swoc_info() requests sizeof(struct swoc_info) (60) bytes
from the device via usb_control_msg(), but its callers only treat a
negative return value as failure. A device that answers the
vendor-specific GetSwocInfo request with a short IN transfer is
therefore accepted, leaving the tail of the freshly allocated
(kmalloc(), non-zeroing) swoc_info buffer uninitialized.
truinst_show() subsequently prints swocInfo->rev, swocInfo->LinuxSKU
and swocInfo->LinuxVer from that buffer into the world-readable
(0444) "truinst" sysfs attribute. An emulated/malicious USB device
(VID 0x1199, PID 0x0fff) can exploit this to disclose up to 5 bytes
of stale kernel heap memory (kmalloc-64) to unprivileged userspace,
once per sysfs read, indefinitely. On kernels built without
init_on_alloc this leaks recently freed heap contents.
Only accept the transfer when the full structure was received.
sierra_ms_init() already retries failed queries, so well-behaved
devices are unaffected.
Fixes: 32fe5e393455 ("USB Storage Sierra: TRU-Install feature update")
Cc: stable <stable@kernel.org>
Signed-off-by: Syed Labeeq Sajid Bukhari <syedlabeeq@gmail.com>
Assisted-by: Kimi:K2 [Kimi Code CLI]
Link: https://patch.msgid.link/20260910140343.49371-1-syedlabeeq@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/storage/sierra_ms.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/usb/storage/sierra_ms.c b/drivers/usb/storage/sierra_ms.c index c5e3eeeb2144..992685ca6f1a 100644 --- a/drivers/usb/storage/sierra_ms.c +++ b/drivers/usb/storage/sierra_ms.c @@ -77,6 +77,13 @@ static int sierra_get_swoc_info(struct usb_device *udev, sizeof(struct swoc_info), /* __u16 size */ USB_CTRL_SET_TIMEOUT); /* int timeout */ + /* + * A short IN transfer leaves the tail of swocInfo uninitialized; + * only a full transfer is valid. + */ + if (result != sizeof(struct swoc_info)) + return -EIO; + swocInfo->LinuxSKU = le16_to_cpu(swocInfo->LinuxSKU); swocInfo->LinuxVer = le16_to_cpu(swocInfo->LinuxVer); return result; |