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a8a572a6b5
Remove the dst_entries_init/destroy calls for xfrm4 and xfrm6 dst_ops templates; their dst_entries counters will never be used. Move the xfrm dst_ops initialization from the common xfrm/xfrm_policy.c to xfrm4/xfrm4_policy.c and xfrm6/xfrm6_policy.c, and call dst_entries_init and dst_entries_destroy for each net namespace. The ipv4 and ipv6 xfrms each create dst_ops template, and perform dst_entries_init on the templates. The template values are copied to each net namespace's xfrm.xfrm*_dst_ops. The problem there is the dst_ops pcpuc_entries field is a percpu counter and cannot be used correctly by simply copying it to another object. The result of this is a very subtle bug; changes to the dst entries counter from one net namespace may sometimes get applied to a different net namespace dst entries counter. This is because of how the percpu counter works; it has a main count field as well as a pointer to the percpu variables. Each net namespace maintains its own main count variable, but all point to one set of percpu variables. When any net namespace happens to change one of the percpu variables to outside its small batch range, its count is moved to the net namespace's main count variable. So with multiple net namespaces operating concurrently, the dst_ops entries counter can stray from the actual value that it should be; if counts are consistently moved from one net namespace to another (which my testing showed is likely), then one net namespace winds up with a negative dst_ops count while another winds up with a continually increasing count, eventually reaching its gc_thresh limit, which causes all new traffic on the net namespace to fail with -ENOBUFS. Signed-off-by: Dan Streetman <dan.streetman@canonical.com> Signed-off-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| xfrm_algo.c | ||
| xfrm_hash.c | ||
| xfrm_hash.h | ||
| xfrm_input.c | ||
| xfrm_ipcomp.c | ||
| xfrm_output.c | ||
| xfrm_policy.c | ||
| xfrm_proc.c | ||
| xfrm_replay.c | ||
| xfrm_state.c | ||
| xfrm_sysctl.c | ||
| xfrm_user.c | ||