CVE-2022-49096

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net: sfc: add missing xdp queue reinitialization<br /> <br /> After rx/tx ring buffer size is changed, kernel panic occurs when<br /> it acts XDP_TX or XDP_REDIRECT.<br /> <br /> When tx/rx ring buffer size is changed(ethtool -G), sfc driver<br /> reallocates and reinitializes rx and tx queues and their buffer<br /> (tx_queue-&gt;buffer).<br /> But it misses reinitializing xdp queues(efx-&gt;xdp_tx_queues).<br /> So, while it is acting XDP_TX or XDP_REDIRECT, it uses the uninitialized<br /> tx_queue-&gt;buffer.<br /> <br /> A new function efx_set_xdp_channels() is separated from efx_set_channels()<br /> to handle only xdp queues.<br /> <br /> Splat looks like:<br /> BUG: kernel NULL pointer dereference, address: 000000000000002a<br /> #PF: supervisor write access in kernel mode<br /> #PF: error_code(0x0002) - not-present page<br /> PGD 0 P4D 0<br /> Oops: 0002 [#4] PREEMPT SMP NOPTI<br /> RIP: 0010:efx_tx_map_chunk+0x54/0x90 [sfc]<br /> CPU: 2 PID: 0 Comm: swapper/2 Tainted: G D 5.17.0+ #55 e8beeee8289528f11357029357cf<br /> Code: 48 8b 8d a8 01 00 00 48 8d 14 52 4c 8d 2c d0 44 89 e0 48 85 c9 74 0e 44 89 e2 4c 89 f6 48 80<br /> RSP: 0018:ffff92f121e45c60 EFLAGS: 00010297<br /> RIP: 0010:efx_tx_map_chunk+0x54/0x90 [sfc]<br /> RAX: 0000000000000040 RBX: ffff92ea506895c0 RCX: ffffffffc0330870<br /> RDX: 0000000000000001 RSI: 00000001139b10ce RDI: ffff92ea506895c0<br /> RBP: ffffffffc0358a80 R08: 00000001139b110d R09: 0000000000000000<br /> R10: 0000000000000001 R11: ffff92ea414c0088 R12: 0000000000000040<br /> R13: 0000000000000018 R14: 00000001139b10ce R15: ffff92ea506895c0<br /> FS: 0000000000000000(0000) GS:ffff92f121ec0000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> Code: 48 8b 8d a8 01 00 00 48 8d 14 52 4c 8d 2c d0 44 89 e0 48 85 c9 74 0e 44 89 e2 4c 89 f6 48 80<br /> CR2: 000000000000002a CR3: 00000003e6810004 CR4: 00000000007706e0<br /> RSP: 0018:ffff92f121e85c60 EFLAGS: 00010297<br /> PKRU: 55555554<br /> RAX: 0000000000000040 RBX: ffff92ea50689700 RCX: ffffffffc0330870<br /> RDX: 0000000000000001 RSI: 00000001145a90ce RDI: ffff92ea50689700<br /> RBP: ffffffffc0358a80 R08: 00000001145a910d R09: 0000000000000000<br /> R10: 0000000000000001 R11: ffff92ea414c0088 R12: 0000000000000040<br /> R13: 0000000000000018 R14: 00000001145a90ce R15: ffff92ea50689700<br /> FS: 0000000000000000(0000) GS:ffff92f121e80000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 000000000000002a CR3: 00000003e6810005 CR4: 00000000007706e0<br /> PKRU: 55555554<br /> Call Trace:<br /> <br /> efx_xdp_tx_buffers+0x12b/0x3d0 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]<br /> __efx_rx_packet+0x5c3/0x930 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]<br /> efx_rx_packet+0x28c/0x2e0 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]<br /> efx_ef10_ev_process+0x5f8/0xf40 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]<br /> ? enqueue_task_fair+0x95/0x550<br /> efx_poll+0xc4/0x360 [sfc 84c94b8e32d44d296c17e10a634d3ad454de4ba5]