The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 458ea1c0be991573ec436aa0afa23baacfae101a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024110949-sinner-broadband-3aa8@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 458ea1c0be991573ec436aa0afa23baacfae101a Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab mchehab+huawei@kernel.org Date: Tue, 15 Oct 2024 09:24:24 +0200 Subject: [PATCH] media: av7110: fix a spectre vulnerability
As warned by smatch: drivers/staging/media/av7110/av7110_ca.c:270 dvb_ca_ioctl() warn: potential spectre issue 'av7110->ci_slot' [w] (local cap)
There is a spectre-related vulnerability at the code. Fix it.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org
diff --git a/drivers/staging/media/av7110/av7110.h b/drivers/staging/media/av7110/av7110.h index ec461fd187af..b584754f4be0 100644 --- a/drivers/staging/media/av7110/av7110.h +++ b/drivers/staging/media/av7110/av7110.h @@ -88,6 +88,8 @@ struct infrared { u32 ir_config; };
+#define MAX_CI_SLOTS 2 + /* place to store all the necessary device information */ struct av7110 { /* devices */ @@ -163,7 +165,7 @@ struct av7110 {
/* CA */
- struct ca_slot_info ci_slot[2]; + struct ca_slot_info ci_slot[MAX_CI_SLOTS];
enum av7110_video_mode vidmode; struct dmxdev dmxdev; diff --git a/drivers/staging/media/av7110/av7110_ca.c b/drivers/staging/media/av7110/av7110_ca.c index 6ce212c64e5d..fce4023c9dea 100644 --- a/drivers/staging/media/av7110/av7110_ca.c +++ b/drivers/staging/media/av7110/av7110_ca.c @@ -26,23 +26,28 @@
void CI_handle(struct av7110 *av7110, u8 *data, u16 len) { + unsigned slot_num; + dprintk(8, "av7110:%p\n", av7110);
if (len < 3) return; switch (data[0]) { case CI_MSG_CI_INFO: - if (data[2] != 1 && data[2] != 2) + if (data[2] != 1 && data[2] != MAX_CI_SLOTS) break; + + slot_num = array_index_nospec(data[2] - 1, MAX_CI_SLOTS); + switch (data[1]) { case 0: - av7110->ci_slot[data[2] - 1].flags = 0; + av7110->ci_slot[slot_num].flags = 0; break; case 1: - av7110->ci_slot[data[2] - 1].flags |= CA_CI_MODULE_PRESENT; + av7110->ci_slot[slot_num].flags |= CA_CI_MODULE_PRESENT; break; case 2: - av7110->ci_slot[data[2] - 1].flags |= CA_CI_MODULE_READY; + av7110->ci_slot[slot_num].flags |= CA_CI_MODULE_READY; break; } break; @@ -262,15 +267,19 @@ static int dvb_ca_ioctl(struct file *file, unsigned int cmd, void *parg) case CA_GET_SLOT_INFO: { struct ca_slot_info *info = (struct ca_slot_info *)parg; + unsigned int slot_num;
if (info->num < 0 || info->num > 1) { mutex_unlock(&av7110->ioctl_mutex); return -EINVAL; } - av7110->ci_slot[info->num].num = info->num; - av7110->ci_slot[info->num].type = FW_CI_LL_SUPPORT(av7110->arm_app) ? - CA_CI_LINK : CA_CI; - memcpy(info, &av7110->ci_slot[info->num], sizeof(struct ca_slot_info)); + slot_num = array_index_nospec(info->num, MAX_CI_SLOTS); + + av7110->ci_slot[slot_num].num = info->num; + av7110->ci_slot[slot_num].type = FW_CI_LL_SUPPORT(av7110->arm_app) ? + CA_CI_LINK : CA_CI; + memcpy(info, &av7110->ci_slot[slot_num], + sizeof(struct ca_slot_info)); break; }