kernel/linux.git/net/9p, branch v5.10.257

net/9p: fix double req put in p9_fd_cancelled

2025-10-29T13:01:14+00:00

[ Upstream commit 674b56aa57f9379854cb6798c3bbcef7e7b51ab7 ] Syzkaller reports a KASAN issue as below: general protection fault, probably for non-canonical address 0xfbd59c0000000021: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0xdead000000000108-0xdead00000000010f] CPU: 0 PID: 5083 Comm: syz-executor.2 Not tainted 6.1.134-syzkaller-00037-g855bd1d7d838 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:__list_del include/linux/list.h:114 [inline] RIP: 0010:__list_del_entry include/linux/list.h:137 [inline] RIP: 0010:list_del include/linux/list.h:148 [inline] RIP: 0010:p9_fd_cancelled+0xe9/0x200 net/9p/trans_fd.c:734 Call Trace: p9_client_flush+0x351/0x440 net/9p/client.c:614 p9_client_rpc+0xb6b/0xc70 net/9p/client.c:734 p9_client_version net/9p/client.c:920 [inline] p9_client_create+0xb51/0x1240 net/9p/client.c:1027 v9fs_session_init+0x1f0/0x18f0 fs/9p/v9fs.c:408 v9fs_mount+0xba/0xcb0 fs/9p/vfs_super.c:126 legacy_get_tree+0x108/0x220 fs/fs_context.c:632 vfs_get_tree+0x8e/0x300 fs/super.c:1573 do_new_mount fs/namespace.c:3056 [inline] path_mount+0x6a6/0x1e90 fs/namespace.c:3386 do_mount fs/namespace.c:3399 [inline] __do_sys_mount fs/namespace.c:3607 [inline] __se_sys_mount fs/namespace.c:3584 [inline] __x64_sys_mount+0x283/0x300 fs/namespace.c:3584 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 This happens because of a race condition between: - The 9p client sending an invalid flush request and later cleaning it up; - The 9p client in p9_read_work() canceled all pending requests. Thread 1 Thread 2 ... p9_client_create() ... p9_fd_create() ... p9_conn_create() ... // start Thread 2 INIT_WORK(&m->rq, p9_read_work); p9_read_work() ... p9_client_rpc() ... ... p9_conn_cancel() ... spin_lock(&m->req_lock); ... p9_fd_cancelled() ... ... spin_unlock(&m->req_lock); // status rewrite p9_client_cb(m->client, req, REQ_STATUS_ERROR) // first remove list_del(&req->req_list); ... spin_lock(&m->req_lock) ... // second remove list_del(&req->req_list); spin_unlock(&m->req_lock) ... Commit 74d6a5d56629 ("9p/trans_fd: Fix concurrency del of req_list in p9_fd_cancelled/p9_read_work") fixes a concurrency issue in the 9p filesystem client where the req_list could be deleted simultaneously by both p9_read_work and p9_fd_cancelled functions, but for the case where req->status equals REQ_STATUS_RCVD. Update the check for req->status in p9_fd_cancelled to skip processing not just received requests, but anything that is not SENT, as whatever changed the state from SENT also removed the request from its list. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: afd8d6541155 ("9P: Add cancelled() to the transport functions.") Cc: stable@vger.kernel.org Signed-off-by: Nalivayko Sergey Message-ID: <20250715154815.3501030-1-Sergey.Nalivayko@kaspersky.com> [updated the check from status == RECV || status == ERROR to status != SENT] Signed-off-by: Dominique Martinet [ replaced m->req_lock with client->lock ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

9p/xen: fix release of IRQ

2024-12-14T18:48:15+00:00

[ Upstream commit e43c608f40c065b30964f0a806348062991b802d ] Kernel logs indicate an IRQ was double-freed. Pass correct device ID during IRQ release. Fixes: 71ebd71921e45 ("xen/9pfs: connect to the backend") Signed-off-by: Alex Zenla Signed-off-by: Alexander Merritt Signed-off-by: Ariadne Conill Reviewed-by: Juergen Gross Message-ID: <20241121225100.5736-1-alexander@edera.dev> [Dominique: remove confusing variable reset to 0] Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin

9p/xen: fix init sequence

2024-12-14T18:48:14+00:00

[ Upstream commit 7ef3ae82a6ebbf4750967d1ce43bcdb7e44ff74b ] Large amount of mount hangs observed during hotplugging of 9pfs devices. The 9pfs Xen driver attempts to initialize itself more than once, causing the frontend and backend to disagree: the backend listens on a channel that the frontend does not send on, resulting in stalled processing. Only allow initialization of 9p frontend once. Fixes: c15fe55d14b3b ("9p/xen: fix connection sequence") Signed-off-by: Alex Zenla Signed-off-by: Alexander Merritt Signed-off-by: Ariadne Conill Reviewed-by: Juergen Gross Message-ID: <20241119211633.38321-1-alexander@edera.dev> Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin

9p: fix slab cache name creation for real

2024-11-17T13:59:40+00:00

commit a360f311f57a36e96d88fa8086b749159714dcd2 upstream. This was attempted by using the dev_name in the slab cache name, but as Omar Sandoval pointed out, that can be an arbitrary string, eg something like "/dev/root". Which in turn trips verify_dirent_name(), which fails if a filename contains a slash. So just make it use a sequence counter, and make it an atomic_t to avoid any possible races or locking issues. Reported-and-tested-by: Omar Sandoval Link: https://lore.kernel.org/all/ZxafcO8KWMlXaeWE@telecaster.dhcp.thefacebook.com/ Fixes: 79efebae4afc ("9p: Avoid creating multiple slab caches with the same name") Acked-by: Vlastimil Babka Cc: Dominique Martinet Cc: Thorsten Leemhuis Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

9p: Avoid creating multiple slab caches with the same name

2024-11-17T13:59:39+00:00

[ Upstream commit 79efebae4afc2221fa814c3cae001bede66ab259 ] In the spirit of [1], avoid creating multiple slab caches with the same name. Instead, add the dev_name into the mix. [1]: https://lore.kernel.org/all/20240807090746.2146479-1-pedro.falcato@gmail.com/ Signed-off-by: Pedro Falcato Reported-by: syzbot+3c5d43e97993e1fa612b@syzkaller.appspotmail.com Message-ID: <20240807094725.2193423-1-pedro.falcato@gmail.com> Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin

net/9p: fix uninit-value in p9_client_rpc()

2024-06-16T11:32:34+00:00

commit 25460d6f39024cc3b8241b14c7ccf0d6f11a736a 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: 348b59012e5c ("net/9p: Convert net/9p protocol dumps to tracepoints") Signed-off-by: Nikita Zhandarovich Reviewed-by: Christian Schoenebeck Cc: stable@vger.kernel.org Message-ID: <20240408141039.30428-1-n.zhandarovich@fintech.ru> Signed-off-by: Dominique Martinet Signed-off-by: Greg Kroah-Hartman

9p/net: fix possible memory leak in p9_check_errors()

2024-01-05T14:12:29+00:00

commit ce07087964208eee2ca2f9ee4a98f8b5d9027fe6 upstream. When p9pdu_readf() is called with "s?d" attribute, it allocates a pointer that will store a string. But when p9pdu_readf() fails while handling "d" then this pointer will not be freed in p9_check_errors(). Fixes: 51a87c552dfd ("9p: rework client code to use new protocol support functions") Reviewed-by: Christian Schoenebeck Signed-off-by: Hangyu Hua Message-ID: <20231027030302.11927-1-hbh25y@gmail.com> Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin Link: https://bugzilla.kernel.org/show_bug.cgi?id=218235 Signed-off-by: Alexey Panov Signed-off-by: Greg Kroah-Hartman

net: 9p: avoid freeing uninit memory in p9pdu_vreadf

2024-01-05T14:12:28+00:00

commit ff49bf1867578f23a5ffdd38f927f6e1e16796c4 upstream. If some of p9pdu_readf() calls inside case 'T' in p9pdu_vreadf() fails, the error path is not handled properly. *wnames or members of *wnames array may be left uninitialized and invalidly freed. Initialize *wnames to NULL in beginning of case 'T'. Initialize the first *wnames array element to NULL and nullify the failing *wnames element so that the error path freeing loop stops on the first NULL element and doesn't proceed further. Found by Linux Verification Center (linuxtesting.org). Fixes: ace51c4dd2f9 ("9p: add new protocol support code") Signed-off-by: Fedor Pchelkin Message-ID: <20231206200913.16135-1-pchelkin@ispras.ru> Cc: stable@vger.kernel.org Reviewed-by: Simon Horman Reviewed-by: Christian Schoenebeck Signed-off-by: Dominique Martinet Signed-off-by: Greg Kroah-Hartman

9p/trans_fd: Annotate data-racy writes to file::f_flags

2023-11-28T16:54:52+00:00

[ Upstream commit 355f074609dbf3042900ea9d30fcd2b0c323a365 ] syzbot reported: | BUG: KCSAN: data-race in p9_fd_create / p9_fd_create | | read-write to 0xffff888130fb3d48 of 4 bytes by task 15599 on cpu 0: | p9_fd_open net/9p/trans_fd.c:842 [inline] | p9_fd_create+0x210/0x250 net/9p/trans_fd.c:1092 | p9_client_create+0x595/0xa70 net/9p/client.c:1010 | v9fs_session_init+0xf9/0xd90 fs/9p/v9fs.c:410 | v9fs_mount+0x69/0x630 fs/9p/vfs_super.c:123 | legacy_get_tree+0x74/0xd0 fs/fs_context.c:611 | vfs_get_tree+0x51/0x190 fs/super.c:1519 | do_new_mount+0x203/0x660 fs/namespace.c:3335 | path_mount+0x496/0xb30 fs/namespace.c:3662 | do_mount fs/namespace.c:3675 [inline] | __do_sys_mount fs/namespace.c:3884 [inline] | [...] | | read-write to 0xffff888130fb3d48 of 4 bytes by task 15563 on cpu 1: | p9_fd_open net/9p/trans_fd.c:842 [inline] | p9_fd_create+0x210/0x250 net/9p/trans_fd.c:1092 | p9_client_create+0x595/0xa70 net/9p/client.c:1010 | v9fs_session_init+0xf9/0xd90 fs/9p/v9fs.c:410 | v9fs_mount+0x69/0x630 fs/9p/vfs_super.c:123 | legacy_get_tree+0x74/0xd0 fs/fs_context.c:611 | vfs_get_tree+0x51/0x190 fs/super.c:1519 | do_new_mount+0x203/0x660 fs/namespace.c:3335 | path_mount+0x496/0xb30 fs/namespace.c:3662 | do_mount fs/namespace.c:3675 [inline] | __do_sys_mount fs/namespace.c:3884 [inline] | [...] | | value changed: 0x00008002 -> 0x00008802 Within p9_fd_open(), O_NONBLOCK is added to f_flags of the read and write files. This may happen concurrently if e.g. mounting process modifies the fd in another thread. Mark the plain read-modify-writes as intentional data-races, with the assumption that the result of executing the accesses concurrently will always result in the same result despite the accesses themselves not being atomic. Reported-by: syzbot+e441aeeb422763cc5511@syzkaller.appspotmail.com Signed-off-by: Marco Elver Link: https://lore.kernel.org/r/ZO38mqkS0TYUlpFp@elver.google.com Signed-off-by: Dominique Martinet Message-ID: <20231025103445.1248103-1-asmadeus@codewreck.org> Signed-off-by: Sasha Levin

9p: virtio: make sure 'offs' is initialized in zc_request

2023-09-19T10:20:04+00:00

[ Upstream commit 4a73edab69d3a6623f03817fe950a2d9585f80e4 ] Similarly to the previous patch: offs can be used in handle_rerrors without initializing on small payloads; in this case handle_rerrors will not use it because of the size check, but it doesn't hurt to make sure it is zero to please scan-build. This fixes the following warning: net/9p/trans_virtio.c:539:3: warning: 3rd function call argument is an uninitialized value [core.CallAndMessage] handle_rerror(req, in_hdr_len, offs, in_pages); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Reviewed-by: Simon Horman Signed-off-by: Dominique Martinet Signed-off-by: Eric Van Hensbergen Signed-off-by: Sasha Levin