Dear Ivan,
Thank you for your patch and fixing the report.
Am 16.07.25 um 02:37 schrieb Ivan Pravdin:
Personally, I’d start with the problem description.
Create and use new vmalloc'ed buffer with dev_coredumpv. From
dev_coredumpv documentation:
`This function takes ownership of the vmalloc'ed data and will free
it when it is no longer used.`
You could use email/Markdown style citation by prepending the lines with
`> `.
As hdev->dump is used after dev_coredumpv, create temporary buffer to
hold hdev->dump data.
Reported-by: syzbot+ac3c79181f6aecc5120c@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://lore.kernel.org/all/67eaa688.050a0220.1547ec.014a.GAE@xxxxxxxxxx
Add a trace excerpt to the commit message?
Fixes: b257e02ecc46 ("HCI: coredump: Log devcd dumps into the monitor")
Signed-off-by: Ivan Pravdin <ipravdin.official@xxxxxxxxx>
---
v1 -> v2: Changed subject prefix to Bluetooth:
net/bluetooth/coredump.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/net/bluetooth/coredump.c b/net/bluetooth/coredump.c
index 819eacb38762..1232c9a94f95 100644
--- a/net/bluetooth/coredump.c
+++ b/net/bluetooth/coredump.c
@@ -243,6 +243,7 @@ static void hci_devcd_handle_pkt_pattern(struct hci_dev *hdev,
static void hci_devcd_dump(struct hci_dev *hdev)
{
struct sk_buff *skb;
+ char *coredump;
u32 size;
bt_dev_dbg(hdev, "state %d", hdev->dump.state);
@@ -250,7 +251,11 @@ static void hci_devcd_dump(struct hci_dev *hdev)
size = hdev->dump.tail - hdev->dump.head;
/* Emit a devcoredump with the available data */
- dev_coredumpv(&hdev->dev, hdev->dump.head, size, GFP_KERNEL);
+ coredump = vmalloc(size);
+ if (coredump) {
+ memcpy(coredump, hdev->dump.head, size);
+ dev_coredumpv(&hdev->dev, coredump, size, GFP_KERNEL);
+ }
Should it be logged, if allocation fails?
/* Send a copy to monitor as a diagnostic packet */
skb = bt_skb_alloc(size, GFP_ATOMIC);
Kind regards,
Paul
