From: Andrew Kanner <andrew.kanner@xxxxxxxxx> Date: Tue, 3 Oct 2023 01:29:40 +0300 > Syzkaller reported the following issue: > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 2807 at mm/vmalloc.c:3247 __vmalloc_node_range (mm/vmalloc.c:3361) > Modules linked in: > CPU: 0 PID: 2807 Comm: repro Not tainted 6.6.0-rc2+ #12 > Hardware name: Generic DT based system > unwind_backtrace from show_stack (arch/arm/kernel/traps.c:258) > show_stack from dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1)) > dump_stack_lvl from __warn (kernel/panic.c:633 kernel/panic.c:680) > __warn from warn_slowpath_fmt (./include/linux/context_tracking.h:153 kernel/panic.c:700) > warn_slowpath_fmt from __vmalloc_node_range (mm/vmalloc.c:3361 (discriminator 3)) > __vmalloc_node_range from vmalloc_user (mm/vmalloc.c:3478) > vmalloc_user from xskq_create (net/xdp/xsk_queue.c:40) > xskq_create from xsk_setsockopt (net/xdp/xsk.c:953 net/xdp/xsk.c:1286) > xsk_setsockopt from __sys_setsockopt (net/socket.c:2308) > __sys_setsockopt from ret_fast_syscall (arch/arm/kernel/entry-common.S:68) > > xskq_get_ring_size() uses struct_size() macro to safely calculate the > size of struct xsk_queue and q->nentries of desc members. But the > syzkaller repro was able to set q->nentries with the value initially > taken from copy_from_sockptr() high enough to return SIZE_MAX by > struct_size(). The next PAGE_ALIGN(size) is such case will overflow > the size_t value and set it to 0. This will trigger WARN_ON_ONCE in > vmalloc_user() -> __vmalloc_node_range(). > > The issue is reproducible on 32-bit arm kernel. > > Reported-and-tested-by: syzbot+fae676d3cf469331fc89@xxxxxxxxxxxxxxxxxxxxxxxxx > Closes: https://lore.kernel.org/all/000000000000c84b4705fb31741e@xxxxxxxxxx/T/ > Link: https://syzkaller.appspot.com/bug?extid=fae676d3cf469331fc89 > Fixes: 9f78bf330a66 ("xsk: support use vaddr as ring") > Signed-off-by: Andrew Kanner <andrew.kanner@xxxxxxxxx> Reviewed-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx> [...] Thanks, Olek
