From 29bf6e697644970963751c69f1acfef7d1894d4b Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 9 Oct 2025 17:15:13 -0700 Subject: [PATCH] mm: don't spin in add_stack_record when gfp flags don't allow syzbot was able to find the following path: add_stack_record_to_list mm/page_owner.c:182 [inline] inc_stack_record_count mm/page_owner.c:214 [inline] __set_page_owner+0x2c3/0x4a0 mm/page_owner.c:333 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 alloc_pages_nolock_noprof+0x94/0x120 mm/page_alloc.c:7554 Don't spin in add_stack_record_to_list() when it is called from *_nolock() context. Link: https://lkml.kernel.org/r/CAADnVQK_8bNYEA7TJYgwTYR57=TTFagsvRxp62pFzS_z129eTg@mail.gmail.com Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation") Signed-off-by: Alexei Starovoitov Reported-by: syzbot+8259e1d0e3ae8ed0c490@syzkaller.appspotmail.com Reported-by: syzbot+665739f456b28f32b23d@syzkaller.appspotmail.com Acked-by: Vlastimil Babka Reviewed-by: Oscar Salvador Cc: Brendan Jackman Cc: Johannes Weiner Cc: Michal Hocko Cc: Suren Baghdasaryan Cc: Zi Yan Cc: Signed-off-by: Andrew Morton --- mm/page_owner.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/page_owner.c b/mm/page_owner.c index c3ca21132c2c..589ec37c94aa 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -168,6 +168,9 @@ static void add_stack_record_to_list(struct stack_record *stack_record, unsigned long flags; struct stack *stack; + if (!gfpflags_allow_spinning(gfp_mask)) + return; + set_current_in_page_owner(); stack = kmalloc(sizeof(*stack), gfp_nested_mask(gfp_mask)); if (!stack) { -- 2.51.0