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 4DE4617A300 for ; Thu, 27 Feb 2025 02:13:29 +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=1740622409; cv=none; b=X+Tnkf9q/PPX5KoD4bIiaLzQmHv81juvdqtPtZJ/ngtKi3xL+ZEhhyXTEA1nMGdha1jLbjtYyBxq6lw6tWrCxPK9klSG/zq+HlIDF/4hXf+BHqWeTZjAZ451zCbV9yiH6eTGsP22FZUoing+cn82tF0kpeeLtZgJ+g2vNBnHliY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740622409; c=relaxed/simple; bh=fZ99qZd9Ojo2KwKgASs648HBFs4ux19KOd1oFAodeOA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=sOdnAmOnu6X9aYcwBr7hdolly0CDuWmykzM/cpH9d4Zb30Ji0qPWk0GWOaW4ijCEnZkBQBO2cOBE/2+lkyluyld601ZRdMY7vtbt7ys9SM8HM0kkmXn6H1GfhNG236X80e2I5AMIr2Rc6UaBAoFmnrN5Z1MqeI7rdu8gAt8VMPo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wWdipSKT; 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="wWdipSKT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19B14C4CED6; Thu, 27 Feb 2025 02:13:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1740622409; bh=fZ99qZd9Ojo2KwKgASs648HBFs4ux19KOd1oFAodeOA=; h=From:To:Cc:Subject:Date:Reply-to:From; b=wWdipSKTsW0h7YBIhKh8YvViLYMbV7y+v3Vh/F/F3GoxaiJ0NzutDDVkMKK6is9+e TWqGRTemesTKAx46pLTxByg/aVIU6S9Eo9NUBdvpeIO+d6WOOJtLKkRjNWtBHxVuFM SkMNSP7SSKPT9ntR5aKS75JBDCD76iXFal67+Rl0= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2025-21753: btrfs: fix use-after-free when attempting to join an aborted transaction Date: Wed, 26 Feb 2025 18:11:35 -0800 Message-ID: <2025022602-CVE-2025-21753-91bd@gregkh> X-Mailer: git-send-email 2.48.1 Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Reply-to: , X-Developer-Signature: v=1; a=openpgp-sha256; l=11462; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=fZ99qZd9Ojo2KwKgASs648HBFs4ux19KOd1oFAodeOA=; b=owGbwMvMwCRo6H6F97bub03G02pJDOn7T25zOmJ6c/v53B+lqtOUPDvbs7IK57px39J61LtM6 rBL86dpHbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjCRy+cZ5kd81v4UFJeWWFs/ Q5pvvuijxINazgxzpUsbzJqWpNV/4NLsS/vikD1b+fJdAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit Description =========== In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free when attempting to join an aborted transaction When we are trying to join the current transaction and if it's aborted, we read its 'aborted' field after unlocking fs_info->trans_lock and without holding any extra reference count on it. This means that a concurrent task that is aborting the transaction may free the transaction before we read its 'aborted' field, leading to a use-after-free. Fix this by reading the 'aborted' field while holding fs_info->trans_lock since any freeing task must first acquire that lock and set fs_info->running_transaction to NULL before freeing the transaction. This was reported by syzbot and Dmitry with the following stack traces from KASAN: ================================================================== BUG: KASAN: slab-use-after-free in join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278 Read of size 4 at addr ffff888011839024 by task kworker/u4:9/1128 CPU: 0 UID: 0 PID: 1128 Comm: kworker/u4:9 Not tainted 6.13.0-rc7-syzkaller-00019-gc45323b7560e #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events_unbound btrfs_async_reclaim_data_space Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278 start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697 flush_space+0x448/0xcf0 fs/btrfs/space-info.c:803 btrfs_async_reclaim_data_space+0x159/0x510 fs/btrfs/space-info.c:1321 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 5315: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329 kmalloc_noprof include/linux/slab.h:901 [inline] join_transaction+0x144/0xda0 fs/btrfs/transaction.c:308 start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697 btrfs_create_common+0x1b2/0x2e0 fs/btrfs/inode.c:6572 lookup_open fs/namei.c:3649 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_creat fs/open.c:1495 [inline] __se_sys_creat fs/open.c:1489 [inline] __x64_sys_creat+0x123/0x170 fs/open.c:1489 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5336: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kfree+0x196/0x430 mm/slub.c:4761 cleanup_transaction fs/btrfs/transaction.c:2063 [inline] btrfs_commit_transaction+0x2c97/0x3720 fs/btrfs/transaction.c:2598 insert_balance_item+0x1284/0x20b0 fs/btrfs/volumes.c:3757 btrfs_balance+0x992/0x10c0 fs/btrfs/volumes.c:4633 btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888011839000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 36 bytes inside of freed 2048-byte region [ffff888011839000, ffff888011839800) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11838 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801ac42000 ffffea0000493400 dead000000000002 raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801ac42000 ffffea0000493400 dead000000000002 head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000 head: 00fff00000000003 ffffea0000460e01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 57, tgid 57 (kworker/0:2), ts 67248182943, free_ts 67229742023 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558 prep_new_page mm/page_alloc.c:1566 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3476 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753 alloc_pages_mpol_noprof+0x3e1/0x780 mm/mempolicy.c:2269 alloc_slab_page+0x6a/0x110 mm/slub.c:2423 allocate_slab+0x5a/0x2b0 mm/slub.c:2589 new_slab mm/slub.c:2642 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830 __slab_alloc+0x58/0xa0 mm/slub.c:3920 __slab_alloc_node mm/slub.c:3995 [inline] slab_alloc_node mm/slub.c:4156 [inline] __do_kmalloc_node mm/slub.c:4297 [inline] __kmalloc_node_track_caller_noprof+0x2e9/0x4c0 mm/slub.c:4317 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678 alloc_skb include/linux/skbuff.h:1323 [inline] alloc_skb_with_frags+0xc3/0x820 net/core/skbuff.c:6612 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2884 sock_alloc_send_skb include/net/sock.h:1803 [inline] mld_newpack+0x1c3/0xaf0 net/ipv6/mcast.c:1747 add_grhead net/ipv6/mcast.c:1850 [inline] add_grec+0x1492/0x19a0 net/ipv6/mcast.c:1988 mld_send_cr net/ipv6/mcast.c:2114 [inline] mld_ifc_work+0x691/0xd90 net/ipv6/mcast.c:2651 page last free pid 5300 tgid 5300 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2659 __slab_free+0x2c2/0x380 mm/slub.c:4524 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] __do_kmalloc_node mm/slub.c:4297 [inline] __kmalloc_noprof+0x236/0x4c0 mm/slub.c:4310 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] fib_create_info+0xc14/0x25b0 net/ipv4/fib_semantics.c:1435 fib_table_insert+0x1f6/0x1f20 net/ipv4/fib_trie.c:1231 fib_magic+0x3d8/0x620 net/ipv4/fib_frontend.c:1112 fib_add_ifaddr+0x40c/0x5e0 net/ipv4/fib_frontend.c:1156 fib_netdev_event+0x375/0x490 net/ipv4/fib_frontend.c:1494 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 __dev_notify_flags+0x207/0x400 dev_change_flags+0xf0/0x1a0 net/core/dev.c:9045 do_setlink+0xc90/0x4210 net/core/rtnetlink.c:3109 rtnl_changelink net/core/rtnetlink.c:3723 [inline] __rtnl_newlink net/core/rtnetlink.c:3875 [inline] rtnl_newlink+0x1bb6/0x2210 net/core/rtnetlink.c:4012 Memory state around the buggy address: ffff888011838f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888011838f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888011839000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888011839080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888011839100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== The Linux kernel CVE team has assigned CVE-2025-21753 to this issue. Affected and fixed versions =========================== Issue introduced in 3.4 with commit 871383be592ba7e819d27556591e315a0df38cee and fixed in 6.1.129 with commit 6ba4663ada6c6315af23a6669d386146634808ec Issue introduced in 3.4 with commit 871383be592ba7e819d27556591e315a0df38cee and fixed in 6.6.78 with commit 8f5cff471039caa2b088060c074c2bf2081bcb01 Issue introduced in 3.4 with commit 871383be592ba7e819d27556591e315a0df38cee and fixed in 6.12.14 with commit 86d71a026a7f63da905db9add845c8ee88801eca Issue introduced in 3.4 with commit 871383be592ba7e819d27556591e315a0df38cee and fixed in 6.13.3 with commit ce628048390dad80320d5a1f74de6ca1e1be91e7 Issue introduced in 3.4 with commit 871383be592ba7e819d27556591e315a0df38cee and fixed in 6.14-rc2 with commit e2f0943cf37305dbdeaf9846e3c941451bcdef63 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2025-21753 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: fs/btrfs/transaction.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/6ba4663ada6c6315af23a6669d386146634808ec https://git.kernel.org/stable/c/8f5cff471039caa2b088060c074c2bf2081bcb01 https://git.kernel.org/stable/c/86d71a026a7f63da905db9add845c8ee88801eca https://git.kernel.org/stable/c/ce628048390dad80320d5a1f74de6ca1e1be91e7 https://git.kernel.org/stable/c/e2f0943cf37305dbdeaf9846e3c941451bcdef63