diff options
author | Alexei Starovoitov <ast@plumgrid.com> | 2015-05-28 19:26:02 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2015-05-31 00:27:51 -0700 |
commit | abf2e7d6e2e315b32ee00067a69aaad2cf4e1b3f (patch) | |
tree | 073ee9134421f2ab9edcd226a48de1a4bea72554 /fs/file_table.c | |
parent | d1f5f2bb91094c9e6f7c98610d637ffdaedef116 (diff) |
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: 04fd61ab36ec ("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>
Diffstat (limited to 'fs/file_table.c')
0 files changed, 0 insertions, 0 deletions