id = 2758
title = "Out-of-bounds access smc91c111_readb()"
state = "closed"
created_at = "2024-12-31T07:03:52.888Z"
closed_at = "2025-03-13T07:03:13.824Z"
labels = ["Fuzzer", "Networking", "workflow::Patch available"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/2758"
host-os = "Ubuntu"
host-arch = "x86_64"
qemu-version = "commit 7c89e226f8"
guest-os = "n/a"
guest-arch = "ARM"
description = """An out-of-bounds bug was triggered by my fuzzer.

It looks like the code doesn't have boundary checks for `data`'s access.

The error is `hw/net/smc91c111.c:605:24: runtime error: index 2048 out of bounds for type 'uint8_t[2048]' (aka 'unsigned char[2048]')`

It's likely that the line 457 also needs a check."""
reproduce = """```
export QEMU_ARGS="-display none -machine accel=qtest, -m 512M -machine realview-eb"
cat << EOF | ./qemu-system-arm $QEMU_ARGS -qtest /dev/null -qtest stdio
writew 0x4e00000c 0x46084a4a
writel 0x4e00000c 0x5c022fcc
clock_step
writel 0x4e000004 0x2fffa1b1
clock_step
readl 0x4e000008
EOF
```"""
additional = """"""