ALSA: ctxfi: Fix out-of-range access

commit 76c47183224c86e4011048b80f0e2d0d166f01c2 upstream.

The master and next_conj of rcs_ops are used for iterating the
resource list entries, and currently those are supposed to return the
current value.  The problem is that next_conf may go over the last
entry before the loop abort condition is evaluated, and it may return
the "current" value that is beyond the array size.  It was caught
recently as a GPF, for example.

Those return values are, however, never actually evaluated, hence
basically we don't have to consider the current value as the return at
all.  By dropping those return values, the potential out-of-range
access above is also fixed automatically.

This patch changes the return type of master and next_conj callbacks
to void and drop the superfluous code accordingly.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=214985
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211118215729.26257-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/pci/ctxfi/ctamixer.c b/sound/pci/ctxfi/ctamixer.c
index 5fcbb065d8702bd051b3a69789bcfe5b3b5d4da2..d32685ce6c05969a0fe14f52ba11ed292ca81546 100644 (file)
--- a/sound/pci/ctxfi/ctamixer.c
+++ b/sound/pci/ctxfi/ctamixer.c
@@ -27,16 +27,15 @@
 
 #define BLANK_SLOT             4094
 
-static int amixer_master(struct rsc *rsc)
+static void amixer_master(struct rsc *rsc)
 {
        rsc->conj = 0;
-       return rsc->idx = container_of(rsc, struct amixer, rsc)->idx[0];
+       rsc->idx = container_of(rsc, struct amixer, rsc)->idx[0];
 }
 
-static int amixer_next_conj(struct rsc *rsc)
+static void amixer_next_conj(struct rsc *rsc)
 {
        rsc->conj++;
-       return container_of(rsc, struct amixer, rsc)->idx[rsc->conj];
 }
 
 static int amixer_index(const struct rsc *rsc)
@@ -335,16 +334,15 @@ int amixer_mgr_destroy(struct amixer_mgr *amixer_mgr)
 
 /* SUM resource management */
 
-static int sum_master(struct rsc *rsc)
+static void sum_master(struct rsc *rsc)
 {
        rsc->conj = 0;
-       return rsc->idx = container_of(rsc, struct sum, rsc)->idx[0];
+       rsc->idx = container_of(rsc, struct sum, rsc)->idx[0];
 }
 
-static int sum_next_conj(struct rsc *rsc)
+static void sum_next_conj(struct rsc *rsc)
 {
        rsc->conj++;
-       return container_of(rsc, struct sum, rsc)->idx[rsc->conj];
 }
 
 static int sum_index(const struct rsc *rsc)

diff --git a/sound/pci/ctxfi/ctdaio.c b/sound/pci/ctxfi/ctdaio.c
index 7f089cb433e17d6c9dde341d09b328aa471ec0c1..df326b7663a2d3bf9b6c80ee9e42c238836f29f2 100644 (file)
--- a/sound/pci/ctxfi/ctdaio.c
+++ b/sound/pci/ctxfi/ctdaio.c
@@ -55,12 +55,12 @@ static struct daio_rsc_idx idx_20k2[NUM_DAIOTYP] = {
        [SPDIFIO] = {.left = 0x05, .right = 0x85},
 };
 
-static int daio_master(struct rsc *rsc)
+static void daio_master(struct rsc *rsc)
 {
        /* Actually, this is not the resource index of DAIO.
         * For DAO, it is the input mapper index. And, for DAI,
         * it is the output time-slot index. */
-       return rsc->conj = rsc->idx;
+       rsc->conj = rsc->idx;
 }
 
 static int daio_index(const struct rsc *rsc)
@@ -68,19 +68,19 @@ static int daio_index(const struct rsc *rsc)
        return rsc->conj;
 }
 
-static int daio_out_next_conj(struct rsc *rsc)
+static void daio_out_next_conj(struct rsc *rsc)
 {
-       return rsc->conj += 2;
+       rsc->conj += 2;
 }
 
-static int daio_in_next_conj_20k1(struct rsc *rsc)
+static void daio_in_next_conj_20k1(struct rsc *rsc)
 {
-       return rsc->conj += 0x200;
+       rsc->conj += 0x200;
 }
 
-static int daio_in_next_conj_20k2(struct rsc *rsc)
+static void daio_in_next_conj_20k2(struct rsc *rsc)
 {
-       return rsc->conj += 0x100;
+       rsc->conj += 0x100;
 }
 
 static const struct rsc_ops daio_out_rsc_ops = {

diff --git a/sound/pci/ctxfi/ctresource.c b/sound/pci/ctxfi/ctresource.c
index 80c4d84f9667f25601c8f7f878cd9c5bde8db05d..f05a09ed42b8da25eb80e7610aaa8c82bea0eff6 100644 (file)
--- a/sound/pci/ctxfi/ctresource.c
+++ b/sound/pci/ctxfi/ctresource.c
@@ -113,18 +113,17 @@ static int audio_ring_slot(const struct rsc *rsc)
     return (rsc->conj << 4) + offset_in_audio_slot_block[rsc->type];
 }
 
-static int rsc_next_conj(struct rsc *rsc)
+static void rsc_next_conj(struct rsc *rsc)
 {
        unsigned int i;
        for (i = 0; (i < 8) && (!(rsc->msr & (0x1 << i))); )
                i++;
        rsc->conj += (AUDIO_SLOT_BLOCK_NUM >> i);
-       return rsc->conj;
 }
 
-static int rsc_master(struct rsc *rsc)
+static void rsc_master(struct rsc *rsc)
 {
-       return rsc->conj = rsc->idx;
+       rsc->conj = rsc->idx;
 }
 
 static const struct rsc_ops rsc_generic_ops = {

diff --git a/sound/pci/ctxfi/ctresource.h b/sound/pci/ctxfi/ctresource.h
index 736d9f7e9e165844fe75419a5e063ad02565814b..29b6fe6de659cffe5093ec242c0ab4f53ad791f0 100644 (file)
--- a/sound/pci/ctxfi/ctresource.h
+++ b/sound/pci/ctxfi/ctresource.h
@@ -43,8 +43,8 @@ struct rsc {
 };
 
 struct rsc_ops {
-       int (*master)(struct rsc *rsc); /* Move to master resource */
-       int (*next_conj)(struct rsc *rsc); /* Move to next conjugate resource */
+       void (*master)(struct rsc *rsc); /* Move to master resource */
+       void (*next_conj)(struct rsc *rsc); /* Move to next conjugate resource */
        int (*index)(const struct rsc *rsc); /* Return the index of resource */
        /* Return the output slot number */
        int (*output_slot)(const struct rsc *rsc);

diff --git a/sound/pci/ctxfi/ctsrc.c b/sound/pci/ctxfi/ctsrc.c
index bb4c9c3c89aee0c26583096b9a23c1b8d986b5d6..93d660276c82ed4283d6c34e2b51e05edb9d2a82 100644 (file)
--- a/sound/pci/ctxfi/ctsrc.c
+++ b/sound/pci/ctxfi/ctsrc.c
@@ -594,16 +594,15 @@ int src_mgr_destroy(struct src_mgr *src_mgr)
 
 /* SRCIMP resource manager operations */
 
-static int srcimp_master(struct rsc *rsc)
+static void srcimp_master(struct rsc *rsc)
 {
        rsc->conj = 0;
-       return rsc->idx = container_of(rsc, struct srcimp, rsc)->idx[0];
+       rsc->idx = container_of(rsc, struct srcimp, rsc)->idx[0];
 }
 
-static int srcimp_next_conj(struct rsc *rsc)
+static void srcimp_next_conj(struct rsc *rsc)
 {
        rsc->conj++;
-       return container_of(rsc, struct srcimp, rsc)->idx[rsc->conj];
 }
 
 static int srcimp_index(const struct rsc *rsc)