From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f171.google.com (mail-yw1-f171.google.com [209.85.128.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4633C1C68F for ; Tue, 30 Jun 2026 10:06:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782814001; cv=none; b=aauupvJtIhxPtmKVGCyy55LHiwMrhts8EDNtINWGKEkyC1W+mBuYAKlhpdc7H7AteUrK3BmI5NpzddPJerZJrhBtoEc9soqF6LhxPiqGctffeEXUKka0B/yX8rcBxUMKL6jlj1KIJqdm0Zw9cxXdotQSucJ4feSsPiN5X9Kv1Vw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782814001; c=relaxed/simple; bh=jLHPncpWDl0+2GMPq5aycjfL2hE5xvIsIfTOWjV86Ak=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=CcoiCoeyHSPiASTSid5pZJqoan8a23gh0rNJoZZs5jgI/RfVq2ifWbyMDxNwGdRso+eVz7i90BE7OBWDeccavvVWz7d+skNQLfpwAa40n2ycaDrbTAO7QYwzbjys7lncS7oL+zgnBssqOupcW8cIgr+3duth8xYazV5JFlHg454= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=nbCkmdtv; arc=none smtp.client-ip=209.85.128.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nbCkmdtv" Received: by mail-yw1-f171.google.com with SMTP id 00721157ae682-804239c418bso41867587b3.0 for ; Tue, 30 Jun 2026 03:06:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1782813998; x=1783418798; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=sMhrCDxHf7aAooYY94uRPeuetG8ov61hCXcWeNIKwUg=; b=nbCkmdtvH7U3XjDz65UKLKoc1LpXnyacN4uuQciKW28jvtyioLkOVJgKznMwD6KzEJ 5rsub8axUdBD/0Zg6cc+kHCGPqCk/OwS9tvaQn7LiWV7QrjLs3JmLlbxMW1Pnutqeo5A kmVnmwO9G0LeFjNw/kp0uXyC7M6d/cEt0fZK5j4VMozrqFMvb27jVLDbEa7Ofjzvpdu4 WIXVYZKhfAvnDAKsPRAIMIMaThyEwk6s7wvRbeaGxB4SgxW1SUFHq4vkxpVNrBCGSg0b 12gUeUoZTmmb7qgLZoutdb4dXyB5GunghT03gAnjonPAeX99H5PmNKVsu0VyMyLHlbuv pSfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782813998; x=1783418798; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=sMhrCDxHf7aAooYY94uRPeuetG8ov61hCXcWeNIKwUg=; b=XfK/aOoiBjkgWGpBoGBsksClAcgAXUynce7wq+SZGBSOygSn/Z5RJU1EPKJzqR3g9X kxqKvJ91pCqCKplkNjb17fxr80eQsqZ0woqFjAn+2GBRAcvUzW6zigjAKiUj3e6s62GR MAa9ifJD6eQoyyBGMwRAZ+WsoSbTnppVJFUNCoIOLOi+wjROKLHi3nJ7OVR0+v8a4Jba eD9tzmycGi8ZDSudptMxkCbeJsENhi+VQLeW31lZYJzN322Qp3q1vGY8JyAU5QY2rQlB HbYb2M7d9lJVLVFI0euj4gJ99le0tXwTt91PpRSRZSbwwY4cG0eVIXwqe/fOJ9shqlel xerg== X-Forwarded-Encrypted: i=1; AHgh+RrmcDL5xYt0MlfAOAmKmBYotYnMb210uZWooVo+GM/4fuje4FrfIid+BetY3L1OAiC2OxRXdSU95AV3ZnU=@vger.kernel.org X-Gm-Message-State: AOJu0YzzacKYiD8Cz32b2yy6AEnx6SkTaQP5kVVQVIEUKkCj0kn/21KY 8ALNl4eRYCY2fgeXXUIcLsD7LJysS+0aGemj2WpDfF7/nRFQCictWSlm X-Gm-Gg: AfdE7clFKp1L+9g4ZeO26MwKXsRvw3GpyLZ2O+A+TUitELcPQOopC367RK6nxW/Ggka 0XmEPeVdi/YOyFEoAJwKvbTE4Y5GRjMPEn86yH9y210jOGJkabmUMJ4AU33IBNurFpgO/YXNtzi 98hvcBHweuinYzSIjgsUQyEq2YpXwzx11sJkHbNAC6j0hVzv9NuXUsoKgvTMyp+UTETLuvg+MSM USZkAjUIFH7AySI4uUj00hk6RR1Yv8PQBjhhxMOx2Jw4WswUfAiwNZVeeX4Yw+qKFpbWoDg7sOx ir1WUrEo1uDGMpoHhXiQdo6JFUnwT/Hun+tab/o2vNqP1R8uVlKoePka95rECbU2E7suy4GGyE2 LlL58CU3JE4OSVEd1PoGn/Uq+MkICR+sAD+3EvL5OK1KIdb53p5oCqBajAuG1N+IGviBojVVNVp csa+ZYxpo/Sny3VNrvaA54f5w5PsuXH9gQCcq7 X-Received: by 2002:a05:690c:e373:b0:80c:72a1:fca3 with SMTP id 00721157ae682-810d7ebe061mr34389197b3.16.1782813998261; Tue, 30 Jun 2026 03:06:38 -0700 (PDT) Received: from Dev-Null-MSI ([2a0d:3344:52ac:a808:98a4:4381:be45:536f]) by smtp.gmail.com with ESMTPSA id 00721157ae682-810e7c6e9f3sm8837187b3.19.2026.06.30.03.06.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Jun 2026 03:06:37 -0700 (PDT) From: Yousef Alhouseen To: Carlos Maiolino Cc: "Darrick J . Wong" , linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, syzbot+97f2c05378c5d68dcb8c@syzkaller.appspotmail.com, Yousef Alhouseen Subject: [PATCH v2] xfs: zero newly allocated btree root space Date: Tue, 30 Jun 2026 12:06:21 +0200 Message-ID: <20260630100621.7173-1-alhouseenyousef@gmail.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit xfs_broot_realloc() preserves the existing in-inode btree root while growing its allocation, but leaves the added bytes uninitialized. The inode log formatter copies if_broot_bytes bytes into the journal, so those bytes reach the log record and its CRC calculation before every location has necessarily been overwritten by btree updates. Request __GFP_ZERO for the initial allocation and every subsequent allocation or reallocation, as required by krealloc() semantics. This keeps stale heap contents out of the filesystem log without a separate memset after each growth. Fixes: 6c1c55ac3c05 ("xfs: refactor the inode fork memory allocation functions") Suggested-by: Darrick J. Wong Reported-by: syzbot+97f2c05378c5d68dcb8c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=97f2c05378c5d68dcb8c Cc: stable@vger.kernel.org Signed-off-by: Yousef Alhouseen --- Changes in v2: - Use __GFP_ZERO instead of an explicit memset after krealloc(). - Apply __GFP_ZERO consistently across the allocation lifetime. fs/xfs/libxfs/xfs_inode_fork.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c index 606a36526ce2..dc05540fa85b 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.c +++ b/fs/xfs/libxfs/xfs_inode_fork.c @@ -384,7 +384,8 @@ xfs_broot_alloc( ASSERT(ifp->if_broot == NULL); ifp->if_broot = kmalloc(new_size, - GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL); + GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL | + __GFP_ZERO); ifp->if_broot_bytes = new_size; return ifp->if_broot; } @@ -417,7 +418,8 @@ xfs_broot_realloc( if (ifp->if_broot_bytes > 0 && ifp->if_broot_bytes > new_size) { struct xfs_btree_block *old_broot = ifp->if_broot; - ifp->if_broot = kmalloc(new_size, GFP_KERNEL | __GFP_NOFAIL); + ifp->if_broot = kmalloc(new_size, + GFP_KERNEL | __GFP_NOFAIL | __GFP_ZERO); ifp->if_broot_bytes = new_size; memcpy(ifp->if_broot, old_broot, new_size); kfree(old_broot); @@ -429,7 +431,7 @@ xfs_broot_realloc( * object. */ ifp->if_broot = krealloc(ifp->if_broot, new_size, - GFP_KERNEL | __GFP_NOFAIL); + GFP_KERNEL | __GFP_NOFAIL | __GFP_ZERO); ifp->if_broot_bytes = new_size; return ifp->if_broot; } -- 2.54.0