linux/kernel/bpf
Alexei Starovoitov cdc4e47da8 bpf: avoid copying junk bytes in bpf_get_current_comm()
Lots of places in the kernel use memcpy(buf, comm, TASK_COMM_LEN); but
the result is typically passed to print("%s", buf) and extra bytes
after zero don't cause any harm.
In bpf the result of bpf_get_current_comm() is used as the part of
map key and was causing spurious hash map mismatches.
Use strlcpy() to guarantee zero-terminated string.
bpf verifier checks that output buffer is zero-initialized,
so even for short task names the output buffer don't have junk bytes.
Note it's not a security concern, since kprobe+bpf is root only.

Fixes: ffeedafbf0 ("bpf: introduce current->pid, tgid, uid, gid, comm accessors")
Reported-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09 23:27:30 -05:00
..
arraymap.c bpf: check for reserved flag bits in array and stack maps 2016-03-08 15:28:31 -05:00
core.c bpf: move clearing of A/X into classic to eBPF migration prologue 2015-12-18 16:04:51 -05:00
hashtab.c bpf: pre-allocate hash map elements 2016-03-08 15:28:31 -05:00
helpers.c bpf: avoid copying junk bytes in bpf_get_current_comm() 2016-03-09 23:27:30 -05:00
inode.c bpf, inode: allow for rename and link ops 2015-12-12 18:44:23 -05:00
Makefile bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
percpu_freelist.c bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
percpu_freelist.h bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
stackmap.c bpf: convert stackmap to pre-allocation 2016-03-08 15:28:31 -05:00
syscall.c bpf: bpf_stackmap_copy depends on CONFIG_PERF_EVENTS 2016-03-09 23:26:51 -05:00
verifier.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-02-23 00:09:14 -05:00