In functions snd_soc_get_volsw_sx() or snd_soc_put_volsw_sx(), if the result of (min + max) is negative, then fls() returns signed integer with value as 32. This leads to signed integer overflow as complete operation is considered as signed integer.
UBSAN: Undefined behaviour in sound/soc/soc-ops.c:382:50 signed integer overflow: -2147483648 - 1 cannot be represented in type 'int' Call trace: [<ffffff852f746fe4>] __dump_stack lib/dump_stack.c:15 [inline] [<ffffff852f746fe4>] dump_stack+0xec/0x158 lib/dump_stack.c:51 [<ffffff852f7b5f3c>] ubsan_epilogue+0x18/0x50 lib/ubsan.c:164 [<ffffff852f7b6840>] handle_overflow+0xf8/0x130 lib/ubsan.c:195 [<ffffff852f7b68f0>] __ubsan_handle_sub_overflow+0x34/0x44 lib/ubsan.c:211 [<ffffff85307971a0>] snd_soc_get_volsw_sx+0x1a8/0x1f8 sound/soc/soc-ops.c:382
Typecast the operation to unsigned int to fix the issue.
Signed-off-by: Rohit kumar rohitkr@codeaurora.org --- Changes since v1: Addressed comments given by Takashi.
sound/soc/soc-ops.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/soc/soc-ops.c b/sound/soc/soc-ops.c index 592efb3..f4dc3d4 100644 --- a/sound/soc/soc-ops.c +++ b/sound/soc/soc-ops.c @@ -373,7 +373,7 @@ int snd_soc_get_volsw_sx(struct snd_kcontrol *kcontrol, unsigned int rshift = mc->rshift; int max = mc->max; int min = mc->min; - unsigned int mask = (1 << (fls(min + max) - 1)) - 1; + unsigned int mask = (1U << (fls(min + max) - 1)) - 1; unsigned int val; int ret;
@@ -418,7 +418,7 @@ int snd_soc_put_volsw_sx(struct snd_kcontrol *kcontrol, unsigned int rshift = mc->rshift; int max = mc->max; int min = mc->min; - unsigned int mask = (1 << (fls(min + max) - 1)) - 1; + unsigned int mask = (1U << (fls(min + max) - 1)) - 1; int err = 0; unsigned int val, val_mask, val2 = 0;