From: Yang Shi yang@os.amperecomputing.com
mainline inclusion from mainline-v6.8-rc3 commit 4ef9ad19e17676b9ef071309bc62020e2373705d category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9H84X CVE: NA
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commit efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries") caused two issues [1] [2] reported on 32 bit system or compat userspace.
It doesn't make too much sense to force huge page alignment on 32 bit system due to the constrained virtual address space.
[1] https://lore.kernel.org/linux-mm/d0a136a0-4a31-46bc-adf4-2db109a61672@kernel... [2] https://lore.kernel.org/linux-mm/CAJuCfpHXLdQy1a2B6xN2d7quTYwg2OoZseYPZTRpU0...
Link: https://lkml.kernel.org/r/20240118180505.2914778-1-shy828301@gmail.com Fixes: efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries") Signed-off-by: Yang Shi yang@os.amperecomputing.com Reported-by: Jiri Slaby jirislaby@kernel.org Reported-by: Suren Baghdasaryan surenb@google.com Tested-by: Jiri Slaby jirislaby@kernel.org Tested-by: Suren Baghdasaryan surenb@google.com Reviewed-by: Matthew Wilcox (Oracle) willy@infradead.org Cc: Rik van Riel riel@surriel.com Cc: Christopher Lameter cl@linux.com Signed-off-by: Andrew Morton akpm@linux-foundation.org (cherry picked from commit 4ef9ad19e17676b9ef071309bc62020e2373705d) Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com --- mm/huge_memory.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 4ce2ed00eaa2..3c4189b1a97e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -37,6 +37,7 @@ #include <linux/page_owner.h> #include <linux/sched/sysctl.h> #include <linux/memory-tiers.h> +#include <linux/compat.h>
#include <asm/tlb.h> #include <asm/pgalloc.h> @@ -784,6 +785,9 @@ static unsigned long __thp_get_unmapped_area(struct file *filp, loff_t off_align = round_up(off, size); unsigned long len_pad, ret;
+ if (IS_ENABLED(CONFIG_32BIT) || in_compat_syscall()) + return 0; + if (off_end <= off_align || (off_end - off_align) < size) return 0;