Zekun Shen <bruceshenzk@xxxxxxxxx> wrote: > Unexpected WDCMSG_TARGET_START replay can lead to null-ptr-deref > when ar->tx_cmd->odata is NULL. The patch adds a null check to > prevent such case. > > KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] > ar5523_cmd+0x46a/0x581 [ar5523] > ar5523_probe.cold+0x1b7/0x18da [ar5523] > ? ar5523_cmd_rx_cb+0x7a0/0x7a0 [ar5523] > ? __pm_runtime_set_status+0x54a/0x8f0 > ? _raw_spin_trylock_bh+0x120/0x120 > ? pm_runtime_barrier+0x220/0x220 > ? __pm_runtime_resume+0xb1/0xf0 > usb_probe_interface+0x25b/0x710 > really_probe+0x209/0x5d0 > driver_probe_device+0xc6/0x1b0 > device_driver_attach+0xe2/0x120 > > I found the bug using a custome USBFuzz port. It's a research work > to fuzz USB stack/drivers. I modified it to fuzz ath9k driver only, > providing hand-crafted usb descriptors to QEMU. > > After fixing the code (fourth byte in usb packet) to WDCMSG_TARGET_START, > I got the null-ptr-deref bug. I believe the bug is triggerable whenever > cmd->odata is NULL. After patching, I tested with the same input and no > longer see the KASAN report. > > This was NOT tested on a real device. > > Signed-off-by: Zekun Shen <bruceshenzk@xxxxxxxxx> > Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx> Patch applied to ath-next branch of ath.git, thanks. ae80b6033834 ar5523: Fix null-ptr-deref with unexpected WDCMSG_TARGET_START reply -- https://patchwork.kernel.org/project/linux-wireless/patch/YXsmPQ3awHFLuAj2@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
