linux-kernel - [PATCH v3 14/35] mm/mmap: move VMA locking before vma_adjust_trans

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230216051750.3125598-15-surenb@google.com>
Date:   Wed, 15 Feb 2023 21:17:29 -0800
From:   Suren Baghdasaryan <surenb@...gle.com>
To:     akpm@...ux-foundation.org
Cc:     michel@...pinasse.org, jglisse@...gle.com, mhocko@...e.com,
        vbabka@...e.cz, hannes@...xchg.org, mgorman@...hsingularity.net,
        dave@...olabs.net, willy@...radead.org, liam.howlett@...cle.com,
        peterz@...radead.org, ldufour@...ux.ibm.com, paulmck@...nel.org,
        mingo@...hat.com, will@...nel.org, luto@...nel.org,
        songliubraving@...com, peterx@...hat.com, david@...hat.com,
        dhowells@...hat.com, hughd@...gle.com, bigeasy@...utronix.de,
        kent.overstreet@...ux.dev, punit.agrawal@...edance.com,
        lstoakes@...il.com, peterjung1337@...il.com, rientjes@...gle.com,
        chriscli@...gle.com, axelrasmussen@...gle.com, joelaf@...gle.com,
        minchan@...gle.com, rppt@...nel.org, jannh@...gle.com,
        shakeelb@...gle.com, tatashin@...gle.com, edumazet@...gle.com,
        gthelen@...gle.com, gurua@...gle.com, arjunroy@...gle.com,
        soheil@...gle.com, leewalsh@...gle.com, posk@...gle.com,
        michalechner92@...glemail.com, linux-mm@...ck.org,
        linux-arm-kernel@...ts.infradead.org,
        linuxppc-dev@...ts.ozlabs.org, x86@...nel.org,
        linux-kernel@...r.kernel.org, kernel-team@...roid.com,
        Suren Baghdasaryan <surenb@...gle.com>
Subject: [PATCH v3 14/35] mm/mmap: move VMA locking before vma_adjust_trans_huge
 call

vma_adjust_trans_huge() modifies the VMA and such modifications should
be done after VMA is marked as being written. Therefore move VMA flag
modifications before vma_adjust_trans_huge() so that VMA is marked
before all these modifications.

Signed-off-by: Suren Baghdasaryan <surenb@...gle.com>
---
 mm/mmap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 06c0f6686de8..c5f2ddf17b87 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2910,11 +2910,12 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
 		if (vma_iter_prealloc(vmi))
 			goto unacct_fail;
 
+		/* Set flags first to implicitly lock the VMA before updates */
+		vm_flags_set(vma, VM_SOFTDIRTY);
 		vma_adjust_trans_huge(vma, vma->vm_start, addr + len, 0);
 		init_vma_prep(&vp, vma);
 		vma_prepare(&vp);
 		vma->vm_end = addr + len;
-		vm_flags_set(vma, VM_SOFTDIRTY);
 		vma_iter_store(vmi, vma);
 
 		vma_complete(&vp, vmi, mm);
-- 
2.39.1