aq(4): Fix OOB write in RSS table packing (no link / panic)#2232
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aq(4): Fix OOB write in RSS table packing (no link / panic)#2232DominoTree wants to merge 2 commits into
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Fix an out-of-bounds stack write in aq_hw_rss_set(). RSS table entries are 3 bits (8 queues max), but with more than 8 RX rings rss_table[] holds larger values; the 32-bit write then spills one uint16_t past bitary[] and corrupts the stack, so the NIC never links or the kernel panics. Mask each value to 3 bits and pack 16 bits at a time to keep the write in bounds. Confirmed on AQC107 (firmware 3.1.88) under FreeBSD 15.0-RELEASE: with the OOB write the interface attached but stayed "no carrier"; removed, link negotiates 1000baseT full-duplex and passes traffic. Signed-off-by: Nick Price <nick@spun.io>
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Cross-posted at freebsd/freebsd-ports#522 to fix things for existing users before aq(4) lands |
aq_if_attach_post() built the RSS indirection table with rss_table[i] = i & (rx_rings_count - 1); which assumes rx_rings_count is a power of two. iflib does not guarantee that (queue counts such as 6, 12 or 24 are possible), so the mask left some queues with no entries and skewed the hash distribution. When rx_rings_count was 0 the (count - 1) underflow also turned the mask into a no-op rather than failing safe. Use a modulo over min(rx_rings_count, HW_ATL_RSS_QUEUES_MAX) instead. The redirection-table field is 3 bits wide, so the hardware can only hash across 8 queues regardless of ring count; capping here keeps the table values in range and complements the bounds fix in aq_hw_rss_set(). Signed-off-by: Nick Price <nick@spun.io>
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(Added a second small commit with another RSS fix) |
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Fix an out-of-bounds stack write in aq_hw_rss_set(). RSS table entries are 3 bits (8 queues max), but with more than 8 RX rings rss_table[] holds larger values; the 32-bit write then spills one uint16_t past bitary[] and corrupts the stack, so the NIC never links or the kernel panics. Mask each value to 3 bits and pack 16 bits at a time to keep the write in bounds.
Confirmed on AQC107 (firmware 3.1.88) under FreeBSD 15.0-RELEASE: with the OOB write the interface attached but stayed "no carrier"; removed, link negotiates 1000baseT full-duplex and passes traffic.
cc @emaste