The quilt patch titled Subject: bpf: kmsan: initialize BPF registers with zeroes has been removed from the -mm tree. Its filename was bpf-kmsan-initialize-bpf-registers-with-zeroes.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Alexander Potapenko <glider@xxxxxxxxxx> Subject: bpf: kmsan: initialize BPF registers with zeroes Date: Thu, 15 Sep 2022 17:04:15 +0200 When executing BPF programs, certain registers may get passed uninitialized to helper functions. E.g. when performing a JMP_CALL, registers BPF_R1-BPF_R5 are always passed to the helper, no matter how many of them are actually used. Passing uninitialized values as function parameters is technically undefined behavior, so we work around it by always initializing the registers. Link: https://lkml.kernel.org/r/20220915150417.722975-42-glider@xxxxxxxxxx Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Eric Biggers <ebiggers@xxxxxxxxxx> Cc: Eric Biggers <ebiggers@xxxxxxxxxx> Cc: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: Ilya Leoshkevich <iii@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Michael S. Tsirkin <mst@xxxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Vegard Nossum <vegard.nossum@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/bpf/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/bpf/core.c~bpf-kmsan-initialize-bpf-registers-with-zeroes +++ a/kernel/bpf/core.c @@ -2002,7 +2002,7 @@ out: static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ { \ u64 stack[stack_size / sizeof(u64)]; \ - u64 regs[MAX_BPF_EXT_REG]; \ + u64 regs[MAX_BPF_EXT_REG] = {}; \ \ FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ ARG1 = (u64) (unsigned long) ctx; \ _ Patches currently in -mm which might be from glider@xxxxxxxxxx are