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authorZekun Shen <bruceshenzk@gmail.com>2021-10-29 00:37:49 +0200
committerKalle Valo <kvalo@codeaurora.org>2021-11-12 08:53:57 +0100
commitae80b6033834342601e99f74f6a62ff5092b1cee (patch)
tree7f86a0b3c47d130eeae352635db0d4bc426716d3
parentath11k: enable 802.11 power save mode in station mode (diff)
downloadlinux-ae80b6033834342601e99f74f6a62ff5092b1cee.tar.xz
linux-ae80b6033834342601e99f74f6a62ff5092b1cee.zip
ar5523: Fix null-ptr-deref with unexpected WDCMSG_TARGET_START reply
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> Link: https://lore.kernel.org/r/YXsmPQ3awHFLuAj2@10-18-43-117.dynapool.wireless.nyu.edu
-rw-r--r--drivers/net/wireless/ath/ar5523/ar5523.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c
index 0e9bad33fac8..141c1b5a7b1f 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;