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| author |   Randy Dunlap <rdunlap@infradead.org> | 2020-12-16 17:12:21 -0800 |
|---|---|---|
| committer |   Jiri Kosina <jkosina@suse.cz> | 2021-01-08 14:50:40 +0100 |
| commit | a0312af1f94d13800e63a7d0a66e563582e39aec (patch) | |
| tree | 92af6efdb9a29d2b7bda2fdafd5fda287e2ce8b0 /drivers/hid/hid-core.c | |
| parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid (diff) | |
| download | linux-dev-a0312af1f94d13800e63a7d0a66e563582e39aec.tar.xz linux-dev-a0312af1f94d13800e63a7d0a66e563582e39aec.zip | |
HID: core: detect and skip invalid inputs to snto32()
Prevent invalid (0, 0) inputs to hid-core's snto32() function.
Maybe it is just the dummy device here that is causing this, but
there are hundreds of calls to snto32(0, 0). Having n (bits count)
of 0 is causing the current UBSAN trap with a shift value of
0xffffffff (-1, or n - 1 in this function).
Either of the value to shift being 0 or the bits count being 0 can be
handled by just returning 0 to the caller, avoiding the following
complex shift + OR operations:
return value & (1 << (n - 1)) ? value | (~0U << n) : value;
Fixes: dde5845a529f ("[PATCH] Generic HID layer - code split")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: syzbot+1e911ad71dd4ea72e04a@syzkaller.appspotmail.com
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-input@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid/hid-core.c')
| -rw-r--r-- | drivers/hid/hid-core.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 56172fe6995c..4d0faf77c14b 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1307,6 +1307,9 @@ EXPORT_SYMBOL_GPL(hid_open_report); static s32 snto32(__u32 value, unsigned n) { + if (!value || !n) + return 0; + switch (n) { case 8: return ((__s8)value); case 16: return ((__s16)value); |