From: Alexander Potapenko <glider@xxxxxxxxxx> Subject: lib/test_meminit.c: use GFP_ATOMIC in RCU critical section kmalloc() shouldn't sleep while in RCU critical section, therefore use GFP_ATOMIC instead of GFP_KERNEL. The bug was spotted by the 0day kernel testing robot. Link: http://lkml.kernel.org/r/20190725121703.210874-1-glider@xxxxxxxxxx Fixes: 7e659650cbda ("lib: introduce test_meminit module") Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/test_meminit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/test_meminit.c~test_meminit-use-gfp_atomic-in-rcu-critical-section +++ a/lib/test_meminit.c @@ -222,7 +222,7 @@ static int __init do_kmem_cache_size(siz * Copy the buffer to check that it's not wiped on * free(). */ - buf_copy = kmalloc(size, GFP_KERNEL); + buf_copy = kmalloc(size, GFP_ATOMIC); if (buf_copy) memcpy(buf_copy, buf, size); _
