Messages in this thread | | | Date | Thu, 20 Jan 2022 14:58:10 -0800 | From | Josh Poimboeuf <> | Subject | Re: [PATCH] objtool: check: give big enough buffer for pv_ops |
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On Fri, Jan 14, 2022 at 09:53:07AM +0100, Peter Zijlstra wrote: > On Fri, Jan 14, 2022 at 07:57:56AM +0000, Sergei Trofimovich wrote: > > On gcc-12 build fails flagging possible buffer overflow: > > > > check.c: In function 'validate_call': > > check.c:2865:58: error: '%d' directive output may be truncated writing between 1 and 10 bytes into a region of size 9 [-Werror=format-truncation=] > > 2865 | snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx); > > | ^~ > > > > I think it's a valid warning: > > > > static char pvname[16]; > > int idx; > > ... > > idx = (rel->addend / sizeof(void *)); > > snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx); > > > > we have only 7 chars for %d while it could take up to 9. > > Right, very unlikely to have that many pv_ops, but it doesn't hurt to > fix this. > > Thanks!
Alternatively, 'idx' could just be unsigned char, since pv_ops only has about ~80 entries max, but either way works for me. I'll queue it up.
-- Josh
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