From: Nathan Chancellor <nathan@kernel.org> To: Kees Cook <keescook@chromium.org>, kernel test robot <lkp@intel.com> Cc: clang-built-linux@googlegroups.com, kbuild-all@lists.01.org, Linux Memory Management List <linux-mm@kvack.org> Subject: Re: [linux-next:master 8858/10077] fs/statfs.c:131:3: warning: 'memcpy' will always overflow; destination buffer has size 64, but size argument is 84 Date: Tue, 24 Aug 2021 19:41:50 -0700 [thread overview] Message-ID: <2751fd54-f28e-6318-2fc1-3fa5d4a98b2d@kernel.org> (raw) In-Reply-To: <202108241916.7EFB8D5E1C@keescook> On 8/24/2021 7:17 PM, Kees Cook wrote: > On Wed, Aug 25, 2021 at 05:59:01AM +0800, kernel test robot wrote: >> tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master >> head: 372b2891c15acbf7b90d948b08ac174bde77102c >> commit: 185e297653a7e0431db813764d2efb9ffd09160c [8858/10077] fortify: Explicitly disable Clang support >> config: i386-randconfig-a016-20210824 (attached as .config) >> compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project d26000e4cc2bc65e207a84fa26cb6e374d60aa12) >> reproduce (this is a W=1 build): >> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross >> chmod +x ~/bin/make.cross >> # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=185e297653a7e0431db813764d2efb9ffd09160c >> git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git >> git fetch --no-tags linux-next master >> git checkout 185e297653a7e0431db813764d2efb9ffd09160c >> # save the attached .config to linux build tree >> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=i386 >> >> If you fix the issue, kindly add following tag as appropriate >> Reported-by: kernel test robot <lkp@intel.com> >> >> All warnings (new ones prefixed by >>): >> >> clang-14: warning: optimization flag '-falign-jumps=0' is not supported [-Wignored-optimization-argument] >> In file included from fs/statfs.c:2: >> In file included from include/linux/syscalls.h:76: >> In file included from include/uapi/linux/aio_abi.h:31: >> In file included from include/linux/fs.h:6: >> In file included from include/linux/wait_bit.h:8: >> In file included from include/linux/wait.h:9: >> In file included from include/linux/spinlock.h:51: >> In file included from include/linux/preempt.h:78: >> In file included from arch/x86/include/asm/preempt.h:7: >> In file included from include/linux/thread_info.h:60: >> arch/x86/include/asm/thread_info.h:172:13: warning: calling '__builtin_frame_address' with a nonzero argument is unsafe [-Wframe-address] >> oldframe = __builtin_frame_address(1); >> ^~~~~~~~~~~~~~~~~~~~~~~~~~ >> arch/x86/include/asm/thread_info.h:174:11: warning: calling '__builtin_frame_address' with a nonzero argument is unsafe [-Wframe-address] >> frame = __builtin_frame_address(2); >> ^~~~~~~~~~~~~~~~~~~~~~~~~~ >> In file included from fs/statfs.c:2: >> In file included from include/linux/syscalls.h:87: >> In file included from include/trace/syscall.h:7: >> In file included from include/linux/trace_events.h:10: >> In file included from include/linux/perf_event.h:49: >> In file included from include/linux/ftrace.h:22: >> arch/x86/include/asm/ftrace.h:7:3: error: Compiler does not support fentry? >> # error Compiler does not support fentry? >> ^ I think that this error is why there is a fortify warning below (no idea how) but applying my patch [1] which came out of [2] fixes this error and I do not see any warning in this file with that config. [1]: https://lore.kernel.org/r/20210824022640.2170859-1-nathan@kernel.org [2]: https://lore.kernel.org/r/YSQE2f5teuvKLkON@Ryzen-9-3900X.localdomain/ Cheers, Nathan >> In file included from fs/statfs.c:2: >> In file included from include/linux/syscalls.h:87: >> In file included from include/trace/syscall.h:7: >> In file included from include/linux/trace_events.h:10: >> In file included from include/linux/perf_event.h:49: >> include/linux/ftrace.h:843:9: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] >> addr = CALLER_ADDR1; >> ^~~~~~~~~~~~ >> include/linux/ftrace.h:830:38: note: expanded from macro 'CALLER_ADDR1' >> #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) >> ^~~~~~~~~~~~~~~~~~~~~~~~ >> include/linux/ftrace.h:823:36: note: expanded from macro 'ftrace_return_address' >> # define ftrace_return_address(n) __builtin_return_address(n) >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~ >> include/linux/ftrace.h:846:9: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] >> return CALLER_ADDR2; >> ^~~~~~~~~~~~ >> include/linux/ftrace.h:831:38: note: expanded from macro 'CALLER_ADDR2' >> #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) >> ^~~~~~~~~~~~~~~~~~~~~~~~ >> include/linux/ftrace.h:823:36: note: expanded from macro 'ftrace_return_address' >> # define ftrace_return_address(n) __builtin_return_address(n) >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~ >>>> fs/statfs.c:131:3: warning: 'memcpy' will always overflow; destination buffer has size 64, but size argument is 84 [-Wfortify-source] >> memcpy(&buf, st, sizeof(*st)); >> ^ >> arch/x86/include/asm/string_32.h:182:25: note: expanded from macro 'memcpy' >> #define memcpy(t, f, n) __builtin_memcpy(t, f, n) >> ^ >> 5 warnings and 1 error generated. >> >> >> vim +/memcpy +131 fs/statfs.c >> >> c8b91accfa1059 Al Viro 2011-03-12 125 >> c8b91accfa1059 Al Viro 2011-03-12 126 static int do_statfs_native(struct kstatfs *st, struct statfs __user *p) >> c8b91accfa1059 Al Viro 2011-03-12 127 { >> c8b91accfa1059 Al Viro 2011-03-12 128 struct statfs buf; >> 7ed1ee6118ae77 Al Viro 2010-03-23 129 >> c8b91accfa1059 Al Viro 2011-03-12 130 if (sizeof(buf) == sizeof(*st)) >> c8b91accfa1059 Al Viro 2011-03-12 @131 memcpy(&buf, st, sizeof(*st)); > > Wat. Statement above this makes that assertion impossible. >
WARNING: multiple messages have this Message-ID (diff)
From: Nathan Chancellor <nathan@kernel.org> To: kbuild-all@lists.01.org Subject: Re: [linux-next:master 8858/10077] fs/statfs.c:131:3: warning: 'memcpy' will always overflow; destination buffer has size 64, but size argument is 84 Date: Tue, 24 Aug 2021 19:41:50 -0700 [thread overview] Message-ID: <2751fd54-f28e-6318-2fc1-3fa5d4a98b2d@kernel.org> (raw) In-Reply-To: <202108241916.7EFB8D5E1C@keescook> [-- Attachment #1: Type: text/plain, Size: 6107 bytes --] On 8/24/2021 7:17 PM, Kees Cook wrote: > On Wed, Aug 25, 2021 at 05:59:01AM +0800, kernel test robot wrote: >> tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master >> head: 372b2891c15acbf7b90d948b08ac174bde77102c >> commit: 185e297653a7e0431db813764d2efb9ffd09160c [8858/10077] fortify: Explicitly disable Clang support >> config: i386-randconfig-a016-20210824 (attached as .config) >> compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project d26000e4cc2bc65e207a84fa26cb6e374d60aa12) >> reproduce (this is a W=1 build): >> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross >> chmod +x ~/bin/make.cross >> # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=185e297653a7e0431db813764d2efb9ffd09160c >> git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git >> git fetch --no-tags linux-next master >> git checkout 185e297653a7e0431db813764d2efb9ffd09160c >> # save the attached .config to linux build tree >> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=i386 >> >> If you fix the issue, kindly add following tag as appropriate >> Reported-by: kernel test robot <lkp@intel.com> >> >> All warnings (new ones prefixed by >>): >> >> clang-14: warning: optimization flag '-falign-jumps=0' is not supported [-Wignored-optimization-argument] >> In file included from fs/statfs.c:2: >> In file included from include/linux/syscalls.h:76: >> In file included from include/uapi/linux/aio_abi.h:31: >> In file included from include/linux/fs.h:6: >> In file included from include/linux/wait_bit.h:8: >> In file included from include/linux/wait.h:9: >> In file included from include/linux/spinlock.h:51: >> In file included from include/linux/preempt.h:78: >> In file included from arch/x86/include/asm/preempt.h:7: >> In file included from include/linux/thread_info.h:60: >> arch/x86/include/asm/thread_info.h:172:13: warning: calling '__builtin_frame_address' with a nonzero argument is unsafe [-Wframe-address] >> oldframe = __builtin_frame_address(1); >> ^~~~~~~~~~~~~~~~~~~~~~~~~~ >> arch/x86/include/asm/thread_info.h:174:11: warning: calling '__builtin_frame_address' with a nonzero argument is unsafe [-Wframe-address] >> frame = __builtin_frame_address(2); >> ^~~~~~~~~~~~~~~~~~~~~~~~~~ >> In file included from fs/statfs.c:2: >> In file included from include/linux/syscalls.h:87: >> In file included from include/trace/syscall.h:7: >> In file included from include/linux/trace_events.h:10: >> In file included from include/linux/perf_event.h:49: >> In file included from include/linux/ftrace.h:22: >> arch/x86/include/asm/ftrace.h:7:3: error: Compiler does not support fentry? >> # error Compiler does not support fentry? >> ^ I think that this error is why there is a fortify warning below (no idea how) but applying my patch [1] which came out of [2] fixes this error and I do not see any warning in this file with that config. [1]: https://lore.kernel.org/r/20210824022640.2170859-1-nathan(a)kernel.org [2]: https://lore.kernel.org/r/YSQE2f5teuvKLkON(a)Ryzen-9-3900X.localdomain/ Cheers, Nathan >> In file included from fs/statfs.c:2: >> In file included from include/linux/syscalls.h:87: >> In file included from include/trace/syscall.h:7: >> In file included from include/linux/trace_events.h:10: >> In file included from include/linux/perf_event.h:49: >> include/linux/ftrace.h:843:9: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] >> addr = CALLER_ADDR1; >> ^~~~~~~~~~~~ >> include/linux/ftrace.h:830:38: note: expanded from macro 'CALLER_ADDR1' >> #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) >> ^~~~~~~~~~~~~~~~~~~~~~~~ >> include/linux/ftrace.h:823:36: note: expanded from macro 'ftrace_return_address' >> # define ftrace_return_address(n) __builtin_return_address(n) >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~ >> include/linux/ftrace.h:846:9: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] >> return CALLER_ADDR2; >> ^~~~~~~~~~~~ >> include/linux/ftrace.h:831:38: note: expanded from macro 'CALLER_ADDR2' >> #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) >> ^~~~~~~~~~~~~~~~~~~~~~~~ >> include/linux/ftrace.h:823:36: note: expanded from macro 'ftrace_return_address' >> # define ftrace_return_address(n) __builtin_return_address(n) >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~ >>>> fs/statfs.c:131:3: warning: 'memcpy' will always overflow; destination buffer has size 64, but size argument is 84 [-Wfortify-source] >> memcpy(&buf, st, sizeof(*st)); >> ^ >> arch/x86/include/asm/string_32.h:182:25: note: expanded from macro 'memcpy' >> #define memcpy(t, f, n) __builtin_memcpy(t, f, n) >> ^ >> 5 warnings and 1 error generated. >> >> >> vim +/memcpy +131 fs/statfs.c >> >> c8b91accfa1059 Al Viro 2011-03-12 125 >> c8b91accfa1059 Al Viro 2011-03-12 126 static int do_statfs_native(struct kstatfs *st, struct statfs __user *p) >> c8b91accfa1059 Al Viro 2011-03-12 127 { >> c8b91accfa1059 Al Viro 2011-03-12 128 struct statfs buf; >> 7ed1ee6118ae77 Al Viro 2010-03-23 129 >> c8b91accfa1059 Al Viro 2011-03-12 130 if (sizeof(buf) == sizeof(*st)) >> c8b91accfa1059 Al Viro 2011-03-12 @131 memcpy(&buf, st, sizeof(*st)); > > Wat. Statement above this makes that assertion impossible. >
next prev parent reply other threads:[~2021-08-25 2:41 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-24 21:59 [linux-next:master 8858/10077] fs/statfs.c:131:3: warning: 'memcpy' will always overflow; destination buffer has size 64, but size argument is 84 kernel test robot 2021-08-24 21:59 ` kernel test robot 2021-08-25 2:17 ` Kees Cook 2021-08-25 2:17 ` Kees Cook 2021-08-25 2:41 ` Nathan Chancellor [this message] 2021-08-25 2:41 ` Nathan Chancellor
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