[linux-stable-rc:linux-5.18.y 467/2461] huge_count_read_write.c:23:9: warning: 'write' reading 4294967295 bytes from a region of size 1

From: kernel test robot
Date: Wed Aug 03 2022 - 03:47:03 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.18.y
head: 7e8a7b1c98057a3014222a505c28c6bd43ed5666
commit: e1ea40d9d6fc3d408390cb42d8f3c9d1466a62f3 [467/2461] selftests/damon: add damon to selftests root Makefile
compiler: gcc-11 (Debian 11.3.0-3) 11.3.0
reproduce:
# https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=e1ea40d9d6fc3d408390cb42d8f3c9d1466a62f3
git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
git fetch --no-tags linux-stable-rc linux-5.18.y
git checkout e1ea40d9d6fc3d408390cb42d8f3c9d1466a62f3
make O=/tmp/kselftest headers
make O=/tmp/kselftest -C tools/testing/selftests

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

huge_count_read_write.c: In function 'write_read_with_huge_count':
>> huge_count_read_write.c:23:9: warning: 'write' reading 4294967295 bytes from a region of size 1 [-Wstringop-overread]
23 | write(filedesc, "", 0xfffffffful);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from huge_count_read_write.c:8:
/usr/include/unistd.h:367:16: note: in a call to function 'write' declared with attribute 'access (read_only, 2, 3)'
367 | extern ssize_t write (int __fd, const void *__buf, size_t __n) __wur
| ^~~~~
>> huge_count_read_write.c:25:15: warning: 'read' writing 4294967295 bytes into a region of size 25 overflows the destination [-Wstringop-overflow=]
25 | ret = read(filedesc, buf, 0xfffffffful);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
huge_count_read_write.c:14:14: note: destination object 'buf' of size 25
14 | char buf[25];
| ^~~
In file included from huge_count_read_write.c:8:
/usr/include/unistd.h:360:16: note: in a call to function 'read' declared with attribute 'access (write_only, 2, 3)'
360 | extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur
| ^~~~

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