The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 61ebe5a747da649057c37be1c37eb934b4af79ca # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024081918-payday-symphonic-ac65@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
61ebe5a747da ("mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0") 88ae5fb755b0 ("mm: vmalloc: enable memory allocation profiling") e9c3cda4d86e ("mm, vmalloc: fix high order __GFP_NOFAIL allocations") 3ba2c3ff98ea ("Merge tag 'modules-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 61ebe5a747da649057c37be1c37eb934b4af79ca Mon Sep 17 00:00:00 2001 From: Hailong Liu hailong.liu@oppo.com Date: Thu, 8 Aug 2024 20:19:56 +0800 Subject: [PATCH] mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0
The __vmap_pages_range_noflush() assumes its argument pages** contains pages with the same page shift. However, since commit e9c3cda4d86e ("mm, vmalloc: fix high order __GFP_NOFAIL allocations"), if gfp_flags includes __GFP_NOFAIL with high order in vm_area_alloc_pages() and page allocation failed for high order, the pages** may contain two different page shifts (high order and order-0). This could lead __vmap_pages_range_noflush() to perform incorrect mappings, potentially resulting in memory corruption.
Users might encounter this as follows (vmap_allow_huge = true, 2M is for PMD_SIZE):
kvmalloc(2M, __GFP_NOFAIL|GFP_X) __vmalloc_node_range_noprof(vm_flags=VM_ALLOW_HUGE_VMAP) vm_area_alloc_pages(order=9) ---> order-9 allocation failed and fallback to order-0 vmap_pages_range() vmap_pages_range_noflush() __vmap_pages_range_noflush(page_shift = 21) ----> wrong mapping happens
We can remove the fallback code because if a high-order allocation fails, __vmalloc_node_range_noprof() will retry with order-0. Therefore, it is unnecessary to fallback to order-0 here. Therefore, fix this by removing the fallback code.
Link: https://lkml.kernel.org/r/20240808122019.3361-1-hailong.liu@oppo.com Fixes: e9c3cda4d86e ("mm, vmalloc: fix high order __GFP_NOFAIL allocations") Signed-off-by: Hailong Liu hailong.liu@oppo.com Reported-by: Tangquan Zheng zhengtangquan@oppo.com Reviewed-by: Baoquan He bhe@redhat.com Reviewed-by: Uladzislau Rezki (Sony) urezki@gmail.com Acked-by: Barry Song baohua@kernel.org Acked-by: Michal Hocko mhocko@suse.com Cc: Matthew Wilcox willy@infradead.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 6b783baf12a1..af2de36549d6 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3584,15 +3584,8 @@ vm_area_alloc_pages(gfp_t gfp, int nid, page = alloc_pages_noprof(alloc_gfp, order); else page = alloc_pages_node_noprof(nid, alloc_gfp, order); - if (unlikely(!page)) { - if (!nofail) - break; - - /* fall back to the zero order allocations */ - alloc_gfp |= __GFP_NOFAIL; - order = 0; - continue; - } + if (unlikely(!page)) + break;
/* * Higher order allocations must be able to be treated as