Re: sdmmc: fix malloc error handling in sdmmc_mem_send_scr()

[Tobias Heider]

On Mon, Jan 10, 2022 at 01:41:53PM +0000, Visa Hankala wrote:
> On Mon, Jan 10, 2022 at 01:12:10PM +0100, Tobias Heider wrote:
> > sdmmc_mem_send_scr() tries to malloc() with M_NOWAIT and returns 0 on
> > error,  which leads to sdmmc_mem_sd_init() passing uninitialized stack
> > memory to sdmmc_mem_decode_scr().
> > The diff below makes sdmmc_mem_send_scr() return ENOMEM if malloc fails.
> > 
> > ok?
> 
> OK visa@
> 
> Isn't there a similar problem with M_NOWAIT in sdmmc_mem_sd_switch()?
> 

Right, here's an updated diff that fixes both.

diff --git a/sys/dev/sdmmc/sdmmc_mem.c b/sys/dev/sdmmc/sdmmc_mem.c
index fae8d63912d..dfb72ec4bf8 100644
--- a/sys/dev/sdmmc/sdmmc_mem.c
+++ b/sys/dev/sdmmc/sdmmc_mem.c
@@ -465,8 +465,10 @@ sdmmc_mem_send_scr(struct sdmmc_softc *sc, uint32_t *scr)
        int error = 0;
 
        ptr = malloc(datalen, M_DEVBUF, M_NOWAIT | M_ZERO);
-       if (ptr == NULL)
+       if (ptr == NULL) {
+               error = ENOMEM;
                goto out;
+       }
 
        memset(&cmd, 0, sizeof(cmd));
        cmd.c_data = ptr;
@@ -607,8 +609,10 @@ sdmmc_mem_sd_switch(struct sdmmc_function *sf, int mode, 
int group,
        gsft = (group - 1) << 2;
 
        ptr = malloc(statlen, M_DEVBUF, M_NOWAIT | M_ZERO);
-       if (ptr == NULL)
+       if (ptr == NULL) {
+               error = ENOMEM;
                goto out;
+       }
 
        memset(&cmd, 0, sizeof(cmd));
        cmd.c_data = ptr;