bpf: fix splat for illegal devmap percpu allocation
It was reported that syzkaller was able to trigger a splat on devmap percpu allocation due to illegal/unsupported allocation request size passed to __alloc_percpu(): [ 70.094249] illegal size (32776) or align (8) for percpu allocation [ 70.094256] ------------[ cut here ]------------ [ 70.094259] WARNING: CPU: 3 PID: 3451 at mm/percpu.c:1365 pcpu_alloc+0x96/0x630 [...] [ 70.094325] Call Trace: [ 70.094328] __alloc_percpu_gfp+0x12/0x20 [ 70.094330] dev_map_alloc+0x134/0x1e0 [ 70.094331] SyS_bpf+0x9bc/0x1610 [ 70.094333] ? selinux_task_setrlimit+0x5a/0x60 [ 70.094334] ? security_task_setrlimit+0x43/0x60 [ 70.094336] entry_SYSCALL_64_fastpath+0x1a/0xa5 This was due to too large max_entries for the map such that we surpassed the upper limit of PCPU_MIN_UNIT_SIZE. It's fine to fail naturally here, so switch to __alloc_percpu_gfp() and pass __GFP_NOWARN instead. Fixes: 11393cc9 ("xdp: Add batching support to redirect map") Reported-by:Mark Rutland <mark.rutland@arm.com> Reported-by:
Shankara Pailoor <sp3485@columbia.edu> Reported-by:
Richard Weinberger <richard@nod.at> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Cc: John Fastabend <john.fastabend@gmail.com> Acked-by:
Alexei Starovoitov <ast@kernel.org> Acked-by:
John Fastabend <john.fastabend@gmail.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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