Messages in this thread | | | From | "Gustavo A. R. Silva" <> | Subject | Re: [PATCH] objtool: check: Fix NULL pointer dereference | Date | Tue, 31 Mar 2020 17:27:40 -0500 |
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On 3/31/20 17:04, Josh Poimboeuf wrote: > On Mon, Mar 30, 2020 at 07:20:40PM -0500, Gustavo A. R. Silva wrote: >> In case func is null, there is a null pointer dereference at 2029: >> >> 2029 WARN("%s uses BP as a scratch register", >> 2030 func->name); >> >> Fix this by null-checking func. >> >> Addresses-Coverity-ID: 1492002 ("Dereference after null check") >> Fixes: c705cecc8431 ("objtool: Track original function across branches") >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> >> --- >> tools/objtool/check.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/objtool/check.c b/tools/objtool/check.c >> index e3bb76358148..182cc48fa892 100644 >> --- a/tools/objtool/check.c >> +++ b/tools/objtool/check.c >> @@ -2025,7 +2025,7 @@ static int validate_return(struct symbol *func, struct instruction *insn, struct >> return 1; >> } >> >> - if (state->bp_scratch) { >> + if (func && state->bp_scratch) { >> WARN("%s uses BP as a scratch register", >> func->name); >> return 1; > > We should still do the warning even if there's no func. I'll make a > slightly different patch which unconditionally uses WARN_FUNC(). >
Awesome. :)
> I'll give you Reported-by credit and keep the coverity tag. Thanks! >
Great.
Thanks -- Gustavo
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