tree 1fb4e72fb739c21f5d4165d9d175a5a960b9e520
parent cf71b174d3464c7dc22f86f25d629a8d9d5c3519
author Maciej Fijalkowski <maciej.fijalkowski@intel.com> 1600290607 +0200
committer Alexei Starovoitov <ast@kernel.org> 1600395560 -0700

bpf: Limit caller's stack depth 256 for subprogs with tailcalls

Protect against potential stack overflow that might happen when bpf2bpf
calls get combined with tailcalls. Limit the caller's stack depth for
such case down to 256 so that the worst case scenario would result in 8k
stack size (32 which is tailcall limit * 256 = 8k).

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>