| Message ID | YXsmPQ3awHFLuAj2@10-18-43-117.dynapool.wireless.nyu.edu (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | ar5523: Fix null-ptr-deref with unexpected WDCMSG_TARGET_START reply | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
Zekun Shen <bruceshenzk@gmail.com> writes: > 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 > > Signed-off-by: Zekun Shen <bruceshenzk@gmail.com> How did you test this?
On Fri, Oct 29, 2021 at 06:53:30AM +0300, Kalle Valo wrote: > Zekun Shen <bruceshenzk@gmail.com> writes: > > > 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 > > > > Signed-off-by: Zekun Shen <bruceshenzk@gmail.com> > > How did you test this? 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. > > -- > https://patchwork.kernel.org/project/linux-wireless/list/ > > https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Zekun Shen <bruceshenzk@gmail.com> writes: > On Fri, Oct 29, 2021 at 06:53:30AM +0300, Kalle Valo wrote: >> Zekun Shen <bruceshenzk@gmail.com> writes: >> >> > 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 >> > >> > Signed-off-by: Zekun Shen <bruceshenzk@gmail.com> >> >> How did you test this? > > 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. Ok, so you didn't test this on a real device at all. I'll mention that in the commit log and also copy what you wrote above.
Zekun Shen <bruceshenzk@gmail.com> 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@gmail.com> > Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Patch applied to ath-next branch of ath.git, thanks. ae80b6033834 ar5523: Fix null-ptr-deref with unexpected WDCMSG_TARGET_START reply
diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c index 49cc4b7ed..1baec4b41 100644 --- a/drivers/net/wireless/ath/ar5523/ar5523.c +++ b/drivers/net/wireless/ath/ar5523/ar5523.c @@ -153,6 +153,10 @@ static void ar5523_cmd_rx_cb(struct urb *urb) ar5523_err(ar, "Invalid reply to WDCMSG_TARGET_START"); return; } + if (!cmd->odata) { + ar5523_err(ar, "Unexpected WDCMSG_TARGET_START reply"); + return; + } memcpy(cmd->odata, hdr + 1, sizeof(u32)); cmd->olen = sizeof(u32); cmd->res = 0;
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 Signed-off-by: Zekun Shen <bruceshenzk@gmail.com> --- drivers/net/wireless/ath/ar5523/ar5523.c | 4 ++++ 1 file changed, 4 insertions(+)