Eric Biggers 709b2d03bb crypto: af_alg - avoid undefined behavior accessing salg_name ... commit 92eb6c3060ebe3adf381fd9899451c5b047bb14d upstream. Commit 3f69cc6076 ("crypto: af_alg - Allow arbitrarily long algorithm names") made the kernel start accepting arbitrarily long algorithm names in sockaddr_alg. However, the actual length of the salg_name field stayed at the original 64 bytes. This is broken because the kernel can access indices >= 64 in salg_name, which is undefined behavior -- even though the memory that is accessed is still located within the sockaddr structure. It would only be defined behavior if the array were properly marked as arbitrary-length (either by making it a flexible array, which is the recommended way these days, or by making it an array of length 0 or 1). We can't simply change salg_name into a flexible array, since that would break source compatibility with userspace programs that embed sockaddr_alg into another struct, or (more commonly) declare a sockaddr_alg like 'struct sockaddr_alg sa = { .salg_name = "foo" };'. One solution would be to change salg_name into a flexible array only when '#ifdef __KERNEL__'. However, that would keep userspace without an easy way to actually use the longer algorithm names. Instead, add a new structure 'sockaddr_alg_new' that has the flexible array field, and expose it to both userspace and the kernel. Make the kernel use it correctly in alg_bind(). This addresses the syzbot report "UBSAN: array-index-out-of-bounds in alg_bind" (https://syzkaller.appspot.com/bug?extid=92ead4eb8e26a26d465e). Reported-by: syzbot+92ead4eb8e26a26d465e@syzkaller.appspotmail.com Fixes: 3f69cc6076 ("crypto: af_alg - Allow arbitrarily long algorithm names") Cc: <stable@vger.kernel.org> # v4.12+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-12-26 16:02:45 +01:00
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acpi
asm-generic	Merge branch 'for-5.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu	2020-11-15 08:57:19 -08:00
clocksource
crypto
drm
dt-bindings
keys
kunit	kunit: fix display of failed expectations for strings	2020-11-10 13:45:15 -07:00
kvm
linux	fscrypt: add fscrypt_is_nokey_name()	2020-12-26 16:02:43 +01:00
math-emu
media
memory
misc
net	Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf	2020-12-10 14:29:30 -08:00
pcmcia
ras
rdma
scsi	scsi: libiscsi: Fix NOP race condition	2020-11-16 22:32:50 -05:00
soc	net: mscc: ocelot: fix dropping of unknown IPv4 multicast on Seville	2020-12-05 15:41:34 -08:00
sound	ASoC: Fixes for v5.11	2020-11-19 19:56:29 +01:00
target
trace	trace: fix potenial dangerous pointer	2020-11-25 13:03:44 +01:00
uapi	crypto: af_alg - avoid undefined behavior accessing salg_name	2020-12-26 16:02:45 +01:00
vdso
video
xen	xen: don't use page->lru for ZONE_DEVICE memory	2020-12-09 10:31:41 +01:00