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authorJia Zhang <zhang.jia@linux.alibaba.com>2018-02-12 17:44:53 +0300
committerIngo Molnar <mingo@kernel.org>2018-02-13 11:15:58 +0300
commit595dd46ebfc10be041a365d0a3fa99df50b6ba73 (patch)
tree3e781a635cad1504225e1753289d7ffecb1d8a6f /arch
parentaec6487e994d2f625197970a56a4aac40c2c7547 (diff)
downloadlinux-595dd46ebfc10be041a365d0a3fa99df50b6ba73.tar.xz
vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page
Commit: df04abfd181a ("fs/proc/kcore.c: Add bounce buffer for ktext data") ... introduced a bounce buffer to work around CONFIG_HARDENED_USERCOPY=y. However, accessing the vsyscall user page will cause an SMAP fault. Replace memcpy() with copy_from_user() to fix this bug works, but adding a common way to handle this sort of user page may be useful for future. Currently, only vsyscall page requires KCORE_USER. Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com> Reviewed-by: Jiri Olsa <jolsa@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1518446694-21124-2-git-send-email-zhang.jia@linux.alibaba.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/mm/init_64.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 1ab42c852069..6aa33d1e198f 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1193,8 +1193,7 @@ void __init mem_init(void)
register_page_bootmem_info();
/* Register memory areas for /proc/kcore */
- kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
- PAGE_SIZE, KCORE_OTHER);
+ kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
mem_init_print_info(NULL);
}