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Manuel Ullmann authored
This will reset deeply on freeze and thaw instead of suspend and resume and prevent null pointer dereferences of the uninitialized ring 0 buffer while thawing. The impact is an indefinitely hanging kernel. You can't switch consoles after this and the only possible user interaction is SysRq. BUG: kernel NULL pointer dereference RIP: 0010:aq_ring_rx_fill+0xcf/0x210 [atlantic] aq_vec_init+0x85/0xe0 [atlantic] aq_nic_init+0xf7/0x1d0 [atlantic] atl_resume_common+0x4f/0x100 [atlantic] pci_pm_thaw+0x42/0xa0 resolves in aq_ring.o to ``` 0000000000000ae0 <aq_ring_rx_fill>: { /* ... */ baf: 48 8b 43 08 mov 0x8(%rbx),%rax buff->flags = 0U; /* buff is NULL */ ``` The bug has been present since the introduction of the new pm code in 8aaa112a ("net: atlantic: refactoring pm logic") and was hidden until 8ce84271 ("net: atlantic: changes for multi-TC support"), which refactored the aq_vec_{free,alloc} functions into aq_vec_{,ring}_{free,alloc}, but is technically not wrong. The original functions just always reinitialized the buffers on S3/S4. If the interface is down before freezing, the bug does not occur. It does not matter, whether the initrd contains and loads the module before thawing. So the fix is to invert the boolean parameter deep in all pm function calls, which was clearly intended to be set like that. First report was on Github [1], which you have to guess from the resume logs in the posted dmesg snippet. Recently I posted one on Bugzilla [2], since I did not have an AQC device so far. #regzbot introduced: 8ce84271 #regzbot from: koo5 <kolman.jindrich@gmail.com> #regzbot monitor: https://github.com/Aquantia/AQtion/issues/32 Fixes: 8aaa112a ("net: atlantic: refactoring pm logic") Link: https://github.com/Aquantia/AQtion/issues/32 [1] Link: https://bugzilla.kernel.org/show_bug.cgi?id=215798 [2] Cc: stable@vger.kernel.org Reported-by:
koo5 <kolman.jindrich@gmail.com> Signed-off-by:
Manuel Ullmann <labre@posteo.de> Signed-off-by:
David S. Miller <davem@davemloft.net>
cbe6c3a8