Vulnerability CVE-2021-47015

Vulnerability CVE-2021-47015

Published: 2024-02-28

Description:

In the Linux kernel, the following vulnerability has been resolved:

bnxt_en: Fix RX consumer index logic in the error path.

In bnxt_rx_pkt(), the RX buffers are expected to complete in order.
If the RX consumer index indicates an out of order buffer completion,
it means we are hitting a hardware bug and the driver will abort all
remaining RX packets and reset the RX ring. The RX consumer index
that we pass to bnxt_discard_rx() is not correct. We should be
passing the current index (tmp_raw_cons) instead of the old index
(raw_cons). This bug can cause us to be at the wrong index when
trying to abort the next RX packet. It can crash like this:

#0 [ffff9bbcdf5c39a8] machine_kexec at ffffffff9b05e007
#1 [ffff9bbcdf5c3a00] __crash_kexec at ffffffff9b111232
#2 [ffff9bbcdf5c3ad0] panic at ffffffff9b07d61e
#3 [ffff9bbcdf5c3b50] oops_end at ffffffff9b030978
#4 [ffff9bbcdf5c3b78] no_context at ffffffff9b06aaf0
#5 [ffff9bbcdf5c3bd8] __bad_area_nosemaphore at ffffffff9b06ae2e
#6 [ffff9bbcdf5c3c28] bad_area_nosemaphore at ffffffff9b06af24
#7 [ffff9bbcdf5c3c38] __do_page_fault at ffffffff9b06b67e
#8 [ffff9bbcdf5c3cb0] do_page_fault at ffffffff9b06bb12
#9 [ffff9bbcdf5c3ce0] page_fault at ffffffff9bc015c5
[exception RIP: bnxt_rx_pkt+237]
RIP: ffffffffc0259cdd RSP: ffff9bbcdf5c3d98 RFLAGS: 00010213
RAX: 000000005dd8097f RBX: ffff9ba4cb11b7e0 RCX: ffffa923cf6e9000
RDX: 0000000000000fff RSI: 0000000000000627 RDI: 0000000000001000
RBP: ffff9bbcdf5c3e60 R8: 0000000000420003 R9: 000000000000020d
R10: ffffa923cf6ec138 R11: ffff9bbcdf5c3e83 R12: ffff9ba4d6f928c0
R13: ffff9ba4cac28080 R14: ffff9ba4cb11b7f0 R15: ffff9ba4d5a30000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018

References:

https://git.kernel.org/stable/c/b1523e4ba293b2a32d9fabaf70c1dcaa6e3e2847

https://git.kernel.org/stable/c/4fcaad2b7dac3f16704f8118c7e481024ddbd3ed

https://git.kernel.org/stable/c/e187ef83c04a5d23e68d39cfdff1a1931e29890c

https://git.kernel.org/stable/c/3fbc5bc651d688fbea2a59cdc91520a2f5334d0a

https://git.kernel.org/stable/c/bbd6f0a948139970f4a615dff189d9a503681a39

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