mISDN: Update parameter type of dsp_cmx_send()

When booting a kernel with CONFIG_MISDN_DSP=y and CONFIG_CFI_CLANG=y,
there is a failure when dsp_cmx_send() is called indirectly from
call_timer_fn():

  [    0.371412] CFI failure at call_timer_fn+0x2f/0x150 (target: dsp_cmx_send+0x0/0x530; expected type: 0x92ada1e9)

The function pointer prototype that call_timer_fn() expects is

  void (*fn)(struct timer_list *)

whereas dsp_cmx_send() has a parameter type of 'void *', which causes
the control flow integrity checks to fail because the parameter types do
not match.

Change dsp_cmx_send()'s parameter type to be 'struct timer_list' to
match the expected prototype. The argument is unused anyways, so this
has no functional change, aside from avoiding the CFI failure.

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202308020936.58787e6c-oliver.sang@intel.com
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Fixes: e313ac12eb13 ("mISDN: Convert timers to use timer_setup()")
Link: https://lore.kernel.org/r/20230802-fix-dsp_cmx_send-cfi-failure-v1-1-2f2e79b0178d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/isdn/mISDN/dsp.h b/drivers/isdn/mISDN/dsp.h
index fa09d511a8eda23cfc65ac42c1a998659584d559..baf31258f5c900654565da9f9659bee9e900a412 100644 (file)
--- a/drivers/isdn/mISDN/dsp.h
+++ b/drivers/isdn/mISDN/dsp.h
@@ -247,7 +247,7 @@ extern void dsp_cmx_hardware(struct dsp_conf *conf, struct dsp *dsp);
 extern int dsp_cmx_conf(struct dsp *dsp, u32 conf_id);
 extern void dsp_cmx_receive(struct dsp *dsp, struct sk_buff *skb);
 extern void dsp_cmx_hdlc(struct dsp *dsp, struct sk_buff *skb);
-extern void dsp_cmx_send(void *arg);
+extern void dsp_cmx_send(struct timer_list *arg);
 extern void dsp_cmx_transmit(struct dsp *dsp, struct sk_buff *skb);
 extern int dsp_cmx_del_conf_member(struct dsp *dsp);
 extern int dsp_cmx_del_conf(struct dsp_conf *conf);

diff --git a/drivers/isdn/mISDN/dsp_cmx.c b/drivers/isdn/mISDN/dsp_cmx.c
index 357b87592eb48c598afe0ef3d4cac81ba7542d7f..61cb45c5d0d8403d0c8dc61eb31ce04f4acca460 100644 (file)
--- a/drivers/isdn/mISDN/dsp_cmx.c
+++ b/drivers/isdn/mISDN/dsp_cmx.c
@@ -1614,7 +1614,7 @@ static u16        dsp_count; /* last sample count */
 static int     dsp_count_valid; /* if we have last sample count */
 
 void
-dsp_cmx_send(void *arg)
+dsp_cmx_send(struct timer_list *arg)
 {
        struct dsp_conf *conf;
        struct dsp_conf_member *member;

diff --git a/drivers/isdn/mISDN/dsp_core.c b/drivers/isdn/mISDN/dsp_core.c
index 386084530c2f85346ce164d1705918b0417eb5dc..fae95f166688336bf60850b0588f6add0f1ca352 100644 (file)
--- a/drivers/isdn/mISDN/dsp_core.c
+++ b/drivers/isdn/mISDN/dsp_core.c
@@ -1195,7 +1195,7 @@ static int __init dsp_init(void)
        }
 
        /* set sample timer */
-       timer_setup(&dsp_spl_tl, (void *)dsp_cmx_send, 0);
+       timer_setup(&dsp_spl_tl, dsp_cmx_send, 0);
        dsp_spl_tl.expires = jiffies + dsp_tics;
        dsp_spl_jiffies = dsp_spl_tl.expires;
        add_timer(&dsp_spl_tl);