a12d215482
[ Upstream commit 223a960c01227e4dbcb6f9fa06b47d73bda21274 ] When using 16K DMA buffers and ring mode, the DES3 refill is not working correctly as the function is using a bogus pointer for checking the private data. As a result stale pointers will remain in the RX descriptor ring, so DMA will now likely overwrite/corrupt some already freed memory. As simple reproducer, just receive some UDP traffic: # ifconfig eth0 down; ifconfig eth0 mtu 9000; ifconfig eth0 up # iperf3 -c 192.168.253.40 -u -b 0 -R If you didn't crash by now check the RX descriptors to find non-contiguous RX buffers: cat /sys/kernel/debug/stmmaceth/eth0/descriptors_status [...] 1 [0x2be5020]: 0xa3220321 0x9ffc1ffc 0x72d70082 0x130e207e ^^^^^^^^^^^^^^^^^^^^^ 2 [0x2be5040]: 0xa3220321 0x9ffc1ffc 0x72998082 0x1311a07e ^^^^^^^^^^^^^^^^^^^^^ A simple ping test will now report bad data: # ping -s 8200 192.168.253.40 PING 192.168.253.40 (192.168.253.40) 8200(8228) bytes of data. 8208 bytes from 192.168.253.40: icmp_seq=1 ttl=64 time=1.00 ms wrong data byte #8144 should be 0xd0 but was 0x88 Fix the wrong pointer. Also we must refill DES3 only if the DMA buffer size is 16K. Fixes: 54139cf3bb33 ("net: stmmac: adding multiple buffers for rx") Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> Acked-by: Jose Abreu <joabreu@synopsys.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.