Nikita Zhandarovich 6c1791130b net/9p: fix uninit-value in p9_client_rpc() ... commit 25460d6f39 upstream. Syzbot with the help of KMSAN reported the following error: BUG: KMSAN: uninit-value in trace_9p_client_res include/trace/events/9p.h:146 [inline] BUG: KMSAN: uninit-value in p9_client_rpc+0x1314/0x1340 net/9p/client.c:754 trace_9p_client_res include/trace/events/9p.h:146 [inline] p9_client_rpc+0x1314/0x1340 net/9p/client.c:754 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122 legacy_get_tree+0x114/0x290 fs/fs_context.c:662 vfs_get_tree+0xa7/0x570 fs/super.c:1797 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352 path_mount+0x742/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x725/0x810 fs/namespace.c:3875 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was created at: __alloc_pages+0x9d6/0xe70 mm/page_alloc.c:4598 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2175 [inline] allocate_slab mm/slub.c:2338 [inline] new_slab+0x2de/0x1400 mm/slub.c:2391 ___slab_alloc+0x1184/0x33d0 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] kmem_cache_alloc+0x6d3/0xbe0 mm/slub.c:3852 p9_tag_alloc net/9p/client.c:278 [inline] p9_client_prepare_req+0x20a/0x1770 net/9p/client.c:641 p9_client_rpc+0x27e/0x1340 net/9p/client.c:688 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122 legacy_get_tree+0x114/0x290 fs/fs_context.c:662 vfs_get_tree+0xa7/0x570 fs/super.c:1797 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352 path_mount+0x742/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x725/0x810 fs/namespace.c:3875 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 If p9_check_errors() fails early in p9_client_rpc(), req->rc.tag will not be properly initialized. However, trace_9p_client_res() ends up trying to print it out anyway before p9_client_rpc() finishes. Fix this issue by assigning default values to p9_fcall fields such as 'tag' and (just in case KMSAN unearths something new) 'id' during the tag allocation stage. Reported-and-tested-by: syzbot+ff14db38f56329ef68df@syzkaller.appspotmail.com Fixes: 348b59012e ("net/9p: Convert net/9p protocol dumps to tracepoints") Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Cc: stable@vger.kernel.org Message-ID: <20240408141039.30428-1-n.zhandarovich@fintech.ru> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2024-06-16 13:47:41 +02:00
..
client.c	net/9p: fix uninit-value in p9_client_rpc()	2024-06-16 13:47:41 +02:00
error.c	9p: fix a bunch of checkpatch warnings	2021-11-04 21:04:25 +09:00
Kconfig	9p: Remove INET dependency	2023-05-04 21:46:57 +01:00
Makefile	9p/trans_fd: split into dedicated module	2022-01-10 09:58:30 +09:00
mod.c	net/p9: load default transports	2022-01-10 10:00:09 +09:00
protocol.c	net: 9p: avoid freeing uninit memory in p9pdu_vreadf	2024-01-01 12:42:41 +00:00
protocol.h	net/9p: add p9_msg_buf_size()	2022-10-05 07:05:41 +09:00
trans_common.c	9p: fix file headers	2021-11-03 17:45:04 +09:00
trans_common.h	9p: fix a bunch of checkpatch warnings	2021-11-04 21:04:25 +09:00
trans_fd.c	9p/trans_fd: Annotate data-racy writes to file::f_flags	2023-11-28 17:19:46 +00:00
trans_rdma.c	9p/rdma: unmap receive dma buffer in rdma_request()/post_recv()	2023-02-24 13:42:28 +00:00
trans_virtio.c	9p: virtio: skip incrementing unused variable	2023-07-20 19:14:50 +00:00
trans_xen.c	9p/xen : Fix use after free bug in xen_9pfs_front_remove due to race condition	2023-04-02 01:00:31 +00:00