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 035644315A; Mon, 23 Jun 2025 21:41:47 +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=1750714907; cv=none; b=L4etOTQiYoSW58z0pPrN9vIgaGIZkG6fuB7khAaAkqtZ6dMpR8X4REGKss//d1Oauc61FwV4pbjpZFd4ks35fQCfTFmu5y8t6pyJSyAQa6U7+U6jZWTXucPH2S0UAZntBoOJKCOQRjwFxqK5PuxkQcT7+uomRyT7D8RdXWNpb2Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750714907; c=relaxed/simple; bh=MsQ8ZVlJE/8vbr5tJt836ljRBP2AyCjg428o8mE3060=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WUfn0Xfcc6sot4tW3h9z2Ff7C39ebGUdGJ4fUoUZlxlEqXY+izKIhSpJl1qwUX4g1ZmWvFGOQno4Gv1M8SOWTYuxmMVVhUimVaXjBKBN3Nc4In7wo5ZjC0TphYoNgX/3K//Ldboh91tPrj1Ed1WIwmKq+hz3gWX/rgSZAlETsKY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pFdnMgGC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="pFdnMgGC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90FE5C4CEEA; Mon, 23 Jun 2025 21:41:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750714906; bh=MsQ8ZVlJE/8vbr5tJt836ljRBP2AyCjg428o8mE3060=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pFdnMgGCd/oH1geszTmZrUDrCe8/YamGhEG7KPk5wAfFvDOQu5f3FsUVBDc0dsLaE Odck+RaM++ioHVbF1eMMVXSpIQY0vn4lA0K51eIe3nxoZr7XK08eaYX/46lBHU8Nmx 4B/haWXjKSzI2RLc9DRkTmsafbuEOJCYq2Zb49cc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Dylan J. Wolff" , Jiacheng Xu , Dave Kleikamp , Sasha Levin Subject: [PATCH 5.10 240/355] jfs: Fix null-ptr-deref in jfs_ioc_trim Date: Mon, 23 Jun 2025 15:07:21 +0200 Message-ID: <20250623130633.967570590@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250623130626.716971725@linuxfoundation.org> References: <20250623130626.716971725@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dylan Wolff [ Upstream commit a4685408ff6c3e2af366ad9a7274f45ff3f394ee ] [ Syzkaller Report ] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000087: 0000 [#1 KASAN: null-ptr-deref in range [0x0000000000000438-0x000000000000043f] CPU: 2 UID: 0 PID: 10614 Comm: syz-executor.0 Not tainted 6.13.0-rc6-gfbfd64d25c7a-dirty #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Sched_ext: serialise (enabled+all), task: runnable_at=-30ms RIP: 0010:jfs_ioc_trim+0x34b/0x8f0 Code: e7 e8 59 a4 87 fe 4d 8b 24 24 4d 8d bc 24 38 04 00 00 48 8d 93 90 82 fe ff 4c 89 ff 31 f6 RSP: 0018:ffffc900055f7cd0 EFLAGS: 00010206 RAX: 0000000000000087 RBX: 00005866a9e67ff8 RCX: 000000000000000a RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88807c180003 R09: 1ffff1100f830000 R10: dffffc0000000000 R11: ffffed100f830001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000438 FS: 00007fe520225640(0000) GS:ffff8880b7e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005593c91b2c88 CR3: 000000014927c000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? __die_body+0x61/0xb0 ? die_addr+0xb1/0xe0 ? exc_general_protection+0x333/0x510 ? asm_exc_general_protection+0x26/0x30 ? jfs_ioc_trim+0x34b/0x8f0 jfs_ioctl+0x3c8/0x4f0 ? __pfx_jfs_ioctl+0x10/0x10 ? __pfx_jfs_ioctl+0x10/0x10 __se_sys_ioctl+0x269/0x350 ? __pfx___se_sys_ioctl+0x10/0x10 ? do_syscall_64+0xfb/0x210 do_syscall_64+0xee/0x210 ? syscall_exit_to_user_mode+0x1e0/0x330 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe51f4903ad Code: c3 e8 a7 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d RSP: 002b:00007fe5202250c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe51f5cbf80 RCX: 00007fe51f4903ad RDX: 0000000020000680 RSI: 00000000c0185879 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe520225640 R13: 000000000000000e R14: 00007fe51f44fca0 R15: 00007fe52021d000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:jfs_ioc_trim+0x34b/0x8f0 Code: e7 e8 59 a4 87 fe 4d 8b 24 24 4d 8d bc 24 38 04 00 00 48 8d 93 90 82 fe ff 4c 89 ff 31 f6 RSP: 0018:ffffc900055f7cd0 EFLAGS: 00010206 RAX: 0000000000000087 RBX: 00005866a9e67ff8 RCX: 000000000000000a RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88807c180003 R09: 1ffff1100f830000 R10: dffffc0000000000 R11: ffffed100f830001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000438 FS: 00007fe520225640(0000) GS:ffff8880b7e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005593c91b2c88 CR3: 000000014927c000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Kernel panic - not syncing: Fatal exception [ Analysis ] We believe that we have found a concurrency bug in the `fs/jfs` module that results in a null pointer dereference. There is a closely related issue which has been fixed: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d6c1b3599b2feb5c7291f5ac3a36e5fa7cedb234 ... but, unfortunately, the accepted patch appears to still be susceptible to a null pointer dereference under some interleavings. To trigger the bug, we think that `JFS_SBI(ipbmap->i_sb)->bmap` is set to NULL in `dbFreeBits` and then dereferenced in `jfs_ioc_trim`. This bug manifests quite rarely under normal circumstances, but is triggereable from a syz-program. Reported-and-tested-by: Dylan J. Wolff Reported-and-tested-by: Jiacheng Xu Signed-off-by: Dylan J. Wolff Signed-off-by: Jiacheng Xu Signed-off-by: Dave Kleikamp Signed-off-by: Sasha Levin --- fs/jfs/jfs_discard.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/jfs/jfs_discard.c b/fs/jfs/jfs_discard.c index 5f4b305030ad5..4b660296caf39 100644 --- a/fs/jfs/jfs_discard.c +++ b/fs/jfs/jfs_discard.c @@ -86,7 +86,8 @@ int jfs_ioc_trim(struct inode *ip, struct fstrim_range *range) down_read(&sb->s_umount); bmp = JFS_SBI(ip->i_sb)->bmap; - if (minlen > bmp->db_agsize || + if (bmp == NULL || + minlen > bmp->db_agsize || start >= bmp->db_mapsize || range->len < sb->s_blocksize) { up_read(&sb->s_umount); -- 2.39.5