6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
[ Upstream commit d4cdc46ca16a5c78b36c5b9b6ad8cac09d6130a0 ]
iwlegacy uses command buffers with a payload size of 320
bytes (default) or 4092 bytes (huge). The struct il_device_cmd type
describes the default buffers and there is no separate type describing
the huge buffers.
The il_enqueue_hcmd() function works with both default and huge
buffers, and has a memcpy() to the buffer payload. The size of
this copy may exceed 320 bytes when using a huge buffer, which
now results in a run-time warning:
memcpy: detected field-spanning write (size 1014) of single field "&out_cmd->cmd.payload" at drivers/net/wireless/intel/iwlegacy/common.c:3170 (size 320)
To fix this:
- Define a new struct type for huge buffers, with a correctly sized
payload field
- When using a huge buffer in il_enqueue_hcmd(), cast the command
buffer pointer to that type when looking up the payload field
Reported-by: Martin-Éric Racine <martin-eric.racine@xxxxxx>
References: https://bugs.debian.org/1062421
References: https://bugzilla.kernel.org/show_bug.cgi?id=219124
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Fixes: 54d9469bc515 ("fortify: Add run-time WARN for cross-field memcpy()")
Tested-by: Martin-Éric Racine <martin-eric.racine@xxxxxx>
Tested-by: Brandon Nielsen <nielsenb@xxxxxxxxxxx>
Acked-by: Stanislaw Gruszka <stf_xl@xxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
Link: https://patch.msgid.link/ZuIhQRi/791vlUhE@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/wireless/intel/iwlegacy/common.c | 13 ++++++++++++-
drivers/net/wireless/intel/iwlegacy/common.h | 12 ++++++++++++
2 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c
index 96002121bb8b2..9fa38221c4311 100644
--- a/drivers/net/wireless/intel/iwlegacy/common.c
+++ b/drivers/net/wireless/intel/iwlegacy/common.c
@@ -3119,6 +3119,7 @@ il_enqueue_hcmd(struct il_priv *il, struct il_host_cmd *cmd)
struct il_cmd_meta *out_meta;
dma_addr_t phys_addr;
unsigned long flags;
+ u8 *out_payload;
u32 idx;
u16 fix_size;
@@ -3154,6 +3155,16 @@ il_enqueue_hcmd(struct il_priv *il, struct il_host_cmd *cmd)
out_cmd = txq->cmd[idx];
out_meta = &txq->meta[idx];
+ /* The payload is in the same place in regular and huge
+ * command buffers, but we need to let the compiler know when
+ * we're using a larger payload buffer to avoid "field-
+ * spanning write" warnings at run-time for huge commands.
+ */
+ if (cmd->flags & CMD_SIZE_HUGE)
+ out_payload = ((struct il_device_cmd_huge *)out_cmd)->cmd.payload;
+ else
+ out_payload = out_cmd->cmd.payload;
+
if (WARN_ON(out_meta->flags & CMD_MAPPED)) {
spin_unlock_irqrestore(&il->hcmd_lock, flags);
return -ENOSPC;
@@ -3167,7 +3178,7 @@ il_enqueue_hcmd(struct il_priv *il, struct il_host_cmd *cmd)
out_meta->callback = cmd->callback;
out_cmd->hdr.cmd = cmd->id;
- memcpy(&out_cmd->cmd.payload, cmd->data, cmd->len);
+ memcpy(out_payload, cmd->data, cmd->len);
/* At this point, the out_cmd now has all of the incoming cmd
* information */
diff --git a/drivers/net/wireless/intel/iwlegacy/common.h b/drivers/net/wireless/intel/iwlegacy/common.h
index 69687fcf963fc..027dae5619a37 100644
--- a/drivers/net/wireless/intel/iwlegacy/common.h
+++ b/drivers/net/wireless/intel/iwlegacy/common.h
@@ -560,6 +560,18 @@ struct il_device_cmd {
#define TFD_MAX_PAYLOAD_SIZE (sizeof(struct il_device_cmd))
+/**
+ * struct il_device_cmd_huge
+ *
+ * For use when sending huge commands.
+ */
+struct il_device_cmd_huge {
+ struct il_cmd_header hdr; /* uCode API */
+ union {
+ u8 payload[IL_MAX_CMD_SIZE - sizeof(struct il_cmd_header)];
+ } __packed cmd;
+} __packed;
+
struct il_host_cmd {
const void *data;
unsigned long reply_page;
--
2.43.0
