Alexei Starovoitov abf2e7d6e2 bpf: add missing rcu protection when releasing programs from prog_array ... Normally the program attachment place (like sockets, qdiscs) takes care of rcu protection and calls bpf_prog_put() after a grace period. The programs stored inside prog_array may not be attached anywhere, so prog_array needs to take care of preserving rcu protection. Otherwise bpf_tail_call() will race with bpf_prog_put(). To solve that introduce bpf_prog_put_rcu() helper function and use it in 3 places where unattached program can decrement refcnt: closing program fd, deleting/replacing program in prog_array. Fixes: 04fd61ab36 ("bpf: allow bpf programs to tail-call other bpf programs") Reported-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>		2015-05-31 00:27:51 -07:00
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arraymap.c	bpf: add missing rcu protection when releasing programs from prog_array	2015-05-31 00:27:51 -07:00
core.c	bpf: allow bpf programs to tail-call other bpf programs	2015-05-21 17:07:59 -04:00
hashtab.c	ebpf: constify various function pointer structs	2015-03-01 14:05:18 -05:00
helpers.c	ebpf: add helper for obtaining current processor id	2015-03-15 21:57:25 -04:00
Makefile	ebpf: remove kernel test stubs	2015-03-01 14:05:18 -05:00
syscall.c	bpf: add missing rcu protection when releasing programs from prog_array	2015-05-31 00:27:51 -07:00
verifier.c	bpf: allow bpf programs to tail-call other bpf programs	2015-05-21 17:07:59 -04:00