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| author | Arnd Bergmann <arnd@arndb.de> | 2023-07-05 17:02:24 +0300 |
|---|---|---|
| committer | Benjamin Tissoires <bentiss@kernel.org> | 2023-07-09 13:47:37 +0300 |
| commit | 5f151364b1da6bd217632fd4ee8cc24eaf66a497 (patch) | |
| tree | decf1f0c4242d025fc72107ab43be7309963df02 /drivers/hid | |
| parent | f9abdcc617dad5f14bbc2ebe96ee99f3e6de0c4e (diff) | |
| download | linux-5f151364b1da6bd217632fd4ee8cc24eaf66a497.tar.xz | |
HID: hyperv: avoid struct memcpy overrun warning
A previous patch addressed the fortified memcpy warning for most
builds, but I still see this one with gcc-9:
In file included from include/linux/string.h:254,
from drivers/hid/hid-hyperv.c:8:
In function 'fortify_memcpy_chk',
inlined from 'mousevsc_on_receive' at drivers/hid/hid-hyperv.c:272:3:
include/linux/fortify-string.h:583:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
583 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
My guess is that the WARN_ON() itself is what confuses gcc, so it no
longer sees that there is a correct range check. Rework the code in a
way that helps readability and avoids the warning.
Fixes: 542f25a94471 ("HID: hyperv: Replace one-element array with flexible-array member")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230705140242.844167-1-arnd@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Diffstat (limited to 'drivers/hid')
| -rw-r--r-- | drivers/hid/hid-hyperv.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c index 49d4a26895e7..f33485d83d24 100644 --- a/drivers/hid/hid-hyperv.c +++ b/drivers/hid/hid-hyperv.c @@ -258,19 +258,17 @@ static void mousevsc_on_receive(struct hv_device *device, switch (hid_msg_hdr->type) { case SYNTH_HID_PROTOCOL_RESPONSE: + len = struct_size(pipe_msg, data, pipe_msg->size); + /* * While it will be impossible for us to protect against * malicious/buggy hypervisor/host, add a check here to * ensure we don't corrupt memory. */ - if (struct_size(pipe_msg, data, pipe_msg->size) - > sizeof(struct mousevsc_prt_msg)) { - WARN_ON(1); + if (WARN_ON(len > sizeof(struct mousevsc_prt_msg))) break; - } - memcpy(&input_dev->protocol_resp, pipe_msg, - struct_size(pipe_msg, data, pipe_msg->size)); + memcpy(&input_dev->protocol_resp, pipe_msg, len); complete(&input_dev->wait_event); break; |