Vince Weaver <[email protected]> writes: > On Thu, 17 Nov 2016, Vince Weaver wrote: > >> On Thu, 17 Nov 2016, Vince Weaver wrote: >> > > >> > > [ 911.507365] >> > > ================================================================== >> > > [ 911.514824] BUG: KASAN: global-out-of-bounds in >> > > match_token+0x268/0x310 at addr ffffffffb14ad058 >> > > [ 911.523912] Read of size 8 by task perf_fuzzer/20662 >> > > [ 911.528945] Address belongs to variable if_tokens+0x78/0xa0 > > I managed to create a short reproducer that reliably causes the issue on > my skylake test machine.
Thanks a bunch, and ugh, this is embarrassing. >From 139306c3bcf7abf49c51a8e56131aaae51222594 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin <[email protected]> Date: Fri, 18 Nov 2016 13:24:55 +0200 Subject: [PATCH] perf: Fix address filter parser The token table passed into match_token() must be null-terminated, which it currently is not in the perf's address filter string parser, as caught by Vince's perf_fuzzer and KASAN. It doesn't blow up otherwise because of the alignment padding of the table to the next element in the .rodata, which is luck. Fixing by adding a null-terminator to the token table. Signed-off-by: Alexander Shishkin <[email protected]> Fixes: 375637bc524 ("perf/core: Introduce address range filtering") Reported-by: Vince Weaver <[email protected]> Cc: [email protected] # v4.7+ --- kernel/events/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index c6e47e97b3..63c72dee71 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8012,6 +8012,7 @@ static void perf_event_addr_filters_apply(struct perf_event *event) * if <size> is not specified, the range is treated as a single address. */ enum { + IF_ACT_NONE = -1, IF_ACT_FILTER, IF_ACT_START, IF_ACT_STOP, @@ -8035,6 +8036,7 @@ static const match_table_t if_tokens = { { IF_SRC_KERNEL, "%u/%u" }, { IF_SRC_FILEADDR, "%u@%s" }, { IF_SRC_KERNELADDR, "%u" }, + { IF_ACT_NONE, NULL }, }; /* -- 2.10.2
