Daniel Borkmann f1f7714ea5 bpf: rework prog_digest into prog_tag ... Commit 7bd509e311 ("bpf: add prog_digest and expose it via fdinfo/netlink") was recently discussed, partially due to admittedly suboptimal name of "prog_digest" in combination with sha1 hash usage, thus inevitably and rightfully concerns about its security in terms of collision resistance were raised with regards to use-cases. The intended use cases are for debugging resp. introspection only for providing a stable "tag" over the instruction sequence that both kernel and user space can calculate independently. It's not usable at all for making a security relevant decision. So collisions where two different instruction sequences generate the same tag can happen, but ideally at a rather low rate. The "tag" will be dumped in hex and is short enough to introspect in tracepoints or kallsyms output along with other data such as stack trace, etc. Thus, this patch performs a rename into prog_tag and truncates the tag to a short output (64 bits) to make it obvious it's not collision-free. Should in future a hash or facility be needed with a security relevant focus, then we can think about requirements, constraints, etc that would fit to that situation. For now, rework the exposed parts for the current use cases as long as nothing has been released yet. Tested on x86_64 and s390x. Fixes: 7bd509e311 ("bpf: add prog_digest and expose it via fdinfo/netlink") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>		2017-01-16 14:03:31 -05:00
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acpi	More ACPI updates for v4.10-rc1	2016-12-22 10:19:32 -08:00
asm-generic	asm-prototypes: Clear any CPP defines before declaring the functions	2017-01-05 12:57:42 +01:00
clocksource
crypto	This pull contains one set of changes: a conversion of the crypto DocBook	2016-12-17 16:00:34 -08:00
drm	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
dt-bindings	dt-bindings: mfd: Remove TPS65217 interrupts	2016-12-27 10:06:00 -08:00
keys
kvm	clocksource: Use a plain u64 instead of cycle_t	2016-12-25 11:04:12 +01:00
linux	bpf: rework prog_digest into prog_tag	2017-01-16 14:03:31 -05:00
math-emu
media	[media] cec: pass parent device in register(), not allocate()	2016-11-29 12:07:17 -02:00
memory
misc
net	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-12-27 16:04:37 -08:00
pcmcia
ras
rdma	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
rxrpc
scsi	linux: drop __bitwise__ everywhere	2016-12-16 00:13:41 +02:00
soc	powerpc updates for 4.10	2016-12-16 09:26:42 -08:00
sound	sound updates for 4.10-rc1	2016-12-14 11:14:28 -08:00
target	Merge branch 'scsi-target-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/bvanassche/linux	2016-12-21 10:16:05 -08:00
trace	mm: get rid of __GFP_OTHER_NODE	2017-01-10 18:31:55 -08:00
uapi	bpf: rework prog_digest into prog_tag	2017-01-16 14:03:31 -05:00
video
xen	xen: features and fixes for 4.10 rc0	2016-12-13 16:07:55 -08:00
Kbuild