From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1E9D9266576; Sun, 29 Mar 2026 00:41:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774744901; cv=none; b=HlyL+KRp7pckT1PhL2wTsqm+uzK+SrOOP9h+aCA3LmQJ8rsn3V+Hq3z3gXfbcoKZI1Gdsvj3+6CPurEIjXHc8OrBXqw0CR5F91i3wJJb8ZvQBy8M358TJuomUqiCE3vkAhxzqjTVmEm0AEsOvD8e8iA6VqBVdRQ9l5m4JOyoJZg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774744901; c=relaxed/simple; bh=X4FNaUJ1Qt2Ppyb8KjUE4F3oY0k054huvDQQNwKFh7I=; h=Date:To:From:Subject:Message-Id; b=aHwMKUjgRI8FS5olZ9rGZ967MVFWryaY7/UJz4rhyGIB6H2Cz+QA1bPnfgbTH5O/WH5Q0yKlna5D+CMNtp4iQFMPQiad9mfKZlw12rxTtQx4YpWERxyAVIcppsugkuY1DU6XqJmtURb+5VPBuvSlXfa4k4zDlePkVpLVX7FusfM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=PtWcl7Yj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="PtWcl7Yj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB42CC4CEF7; Sun, 29 Mar 2026 00:41:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1774744901; bh=X4FNaUJ1Qt2Ppyb8KjUE4F3oY0k054huvDQQNwKFh7I=; h=Date:To:From:Subject:From; b=PtWcl7YjAhrUzkbzXnwp+ypquZxe7vJPNOHbF5K1dtP1/1i2nxIMU45KTuslrYuId VyMmlDz42TDKMR/QplZJ8mhxshnaezxN9f2nl2vNtF/7sZSPIMib8tjPmP21gDnyTv nf/rud8sDnbf8DViKXvVprFqU/khFtlXXsy6zd5A= Date: Sat, 28 Mar 2026 17:41:40 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,sj@kernel.org,sidhartha.kumar@oracle.com,rppt@kernel.org,peterx@redhat.com,osalvador@suse.de,muchun.song@linux.dev,JonasZhou@zhaoxin.com,jane.chu@oracle.com,hughd@google.com,david@kernel.org,aarcange@redhat.com,jianhuizzzzz@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-userfaultfd-fix-hugetlb-fault-mutex-hash-calculation.patch removed from -mm tree Message-Id: <20260329004140.EB42CC4CEF7@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/userfaultfd: fix hugetlb fault mutex hash calculation has been removed from the -mm tree. Its filename was mm-userfaultfd-fix-hugetlb-fault-mutex-hash-calculation.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: Jianhui Zhou Subject: mm/userfaultfd: fix hugetlb fault mutex hash calculation Date: Tue, 10 Mar 2026 19:05:26 +0800 In mfill_atomic_hugetlb(), linear_page_index() is used to calculate the page index for hugetlb_fault_mutex_hash(). However, linear_page_index() returns the index in PAGE_SIZE units, while hugetlb_fault_mutex_hash() expects the index in huge page units. This mismatch means that different addresses within the same huge page can produce different hash values, leading to the use of different mutexes for the same huge page. This can cause races between faulting threads, which can corrupt the reservation map and trigger the BUG_ON in resv_map_release(). Fix this by introducing hugetlb_linear_page_index(), which returns the page index in huge page granularity, and using it in place of linear_page_index(). Link: https://lkml.kernel.org/r/20260310110526.335749-1-jianhuizzzzz@gmail.com Fixes: a08c7193e4f1 ("mm/filemap: remove hugetlb special casing in filemap.c") Signed-off-by: Jianhui Zhou Reported-by: syzbot+f525fd79634858f478e7@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f525fd79634858f478e7 Acked-by: SeongJae Park Reviewed-by: David Hildenbrand (Arm) Acked-by: Mike Rapoport (Microsoft) Cc: Jane Chu Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: JonasZhou Cc: Muchun Song Cc: Oscar Salvador Cc: Peter Xu Cc: SeongJae Park Cc: Sidhartha Kumar Cc: Signed-off-by: Andrew Morton --- include/linux/hugetlb.h | 17 +++++++++++++++++ mm/userfaultfd.c | 2 +- 2 files changed, 18 insertions(+), 1 deletion(-) --- a/include/linux/hugetlb.h~mm-userfaultfd-fix-hugetlb-fault-mutex-hash-calculation +++ a/include/linux/hugetlb.h @@ -792,6 +792,23 @@ static inline unsigned huge_page_shift(s return h->order + PAGE_SHIFT; } +/** + * hugetlb_linear_page_index() - linear_page_index() but in hugetlb + * page size granularity. + * @vma: the hugetlb VMA + * @address: the virtual address within the VMA + * + * Return: the page offset within the mapping in huge page units. + */ +static inline pgoff_t hugetlb_linear_page_index(struct vm_area_struct *vma, + unsigned long address) +{ + struct hstate *h = hstate_vma(vma); + + return ((address - vma->vm_start) >> huge_page_shift(h)) + + (vma->vm_pgoff >> huge_page_order(h)); +} + static inline bool order_is_gigantic(unsigned int order) { return order > MAX_PAGE_ORDER; --- a/mm/userfaultfd.c~mm-userfaultfd-fix-hugetlb-fault-mutex-hash-calculation +++ a/mm/userfaultfd.c @@ -573,7 +573,7 @@ retry: * in the case of shared pmds. fault mutex prevents * races with other faulting threads. */ - idx = linear_page_index(dst_vma, dst_addr); + idx = hugetlb_linear_page_index(dst_vma, dst_addr); mapping = dst_vma->vm_file->f_mapping; hash = hugetlb_fault_mutex_hash(mapping, idx); mutex_lock(&hugetlb_fault_mutex_table[hash]); _ Patches currently in -mm which might be from jianhuizzzzz@gmail.com are