From: Dan Carpenter <dan.carpenter@linaro.org>
To: oe-kbuild@lists.linux.dev, "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: lkp@intel.com, oe-kbuild-all@lists.linux.dev,
linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org,
Jonathan Cameron <jonathan.cameron@huawei.com>
Subject: [rafael-pm:bleeding-edge 69/72] drivers/acpi/bus.c:339 acpi_osc_handshake() warn: variable dereferenced before check 'cap' (see line 332)
Date: Fri, 26 Dec 2025 16:12:47 +0300 [thread overview]
Message-ID: <202512242052.W4GhDauV-lkp@intel.com> (raw)
tree: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git bleeding-edge
head: e08ef982088f28cd65654693f29ffe430a9d4d66
commit: e5322888e6bf4ec17964a93638c9b14433a2f6f1 [69/72] ACPI: bus: Rework the handling of \_SB._OSC platform features
config: x86_64-randconfig-161-20251224 (https://download.01.org/0day-ci/archive/20251224/202512242052.W4GhDauV-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.4.0-5) 12.4.0
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202512242052.W4GhDauV-lkp@intel.com/
New smatch warnings:
drivers/acpi/bus.c:339 acpi_osc_handshake() warn: variable dereferenced before check 'cap' (see line 332)
drivers/acpi/bus.c:339 acpi_osc_handshake() warn: sizeof(NUMBER)?
Old smatch warnings:
drivers/acpi/bus.c:297 acpi_run_osc() warn: sizeof(NUMBER)?
vim +/cap +339 drivers/acpi/bus.c
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 328 static int acpi_osc_handshake(acpi_handle handle, const char *uuid_str,
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 329 int rev, struct acpi_buffer *cap)
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 330 {
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 331 union acpi_object in_params[4], *out_obj;
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 @332 size_t bufsize = cap->length / sizeof(u32);
^^^^^^^^^^^
The cap pointer is dereferenced here.
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 333 struct acpi_object_list input;
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 334 struct acpi_buffer output;
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 335 u32 *capbuf, *retbuf, test;
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 336 guid_t guid;
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 337 int ret, i;
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 338
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 @339 if (!cap || cap->length < 2 * sizeof(32) || guid_parse(uuid_str, &guid))
^^^^
Checked too late.
^^^^^^^^^^
Also this sizeof(32) should be sizeof(u32) although both are the same
so the current code works.
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 340 return -EINVAL;
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 341
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 342 /* First evaluate _OSC with OSC_QUERY_ENABLE set. */
e5322888e6bf4e Rafael J. Wysocki 2025-12-22 343 capbuf = cap->pointer;
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next reply other threads:[~2025-12-26 13:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-26 13:12 Dan Carpenter [this message]
2025-12-26 13:17 ` [rafael-pm:bleeding-edge 69/72] drivers/acpi/bus.c:339 acpi_osc_handshake() warn: variable dereferenced before check 'cap' (see line 332) Rafael J. Wysocki
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