kernel.git/drivers/misc/vmw_vmci/vmci_host.c, branch linux-rolling-stable

VMCI: fix race between vmci_host_setup_notify and vmci_ctx_unset_notify

2025-06-19T13:41:04Z

commit 1bd6406fb5f36c2bb1e96e27d4c3e9f4d09edde4 upstream. During our test, it is found that a warning can be trigger in try_grab_folio as follow: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1678 at mm/gup.c:147 try_grab_folio+0x106/0x130 Modules linked in: CPU: 0 UID: 0 PID: 1678 Comm: syz.3.31 Not tainted 6.15.0-rc5 #163 PREEMPT(undef) RIP: 0010:try_grab_folio+0x106/0x130 Call Trace: follow_huge_pmd+0x240/0x8e0 follow_pmd_mask.constprop.0.isra.0+0x40b/0x5c0 follow_pud_mask.constprop.0.isra.0+0x14a/0x170 follow_page_mask+0x1c2/0x1f0 __get_user_pages+0x176/0x950 __gup_longterm_locked+0x15b/0x1060 ? gup_fast+0x120/0x1f0 gup_fast_fallback+0x17e/0x230 get_user_pages_fast+0x5f/0x80 vmci_host_unlocked_ioctl+0x21c/0xf80 RIP: 0033:0x54d2cd ---[ end trace 0000000000000000 ]--- Digging into the source, context->notify_page may init by get_user_pages_fast and can be seen in vmci_ctx_unset_notify which will try to put_page. However get_user_pages_fast is not finished here and lead to following try_grab_folio warning. The race condition is shown as follow: cpu0 cpu1 vmci_host_do_set_notify vmci_host_setup_notify get_user_pages_fast(uva, 1, FOLL_WRITE, &context->notify_page); lockless_pages_from_mm gup_pgd_range gup_huge_pmd // update &context->notify_page vmci_host_do_set_notify vmci_ctx_unset_notify notify_page = context->notify_page; if (notify_page) put_page(notify_page); // page is freed __gup_longterm_locked __get_user_pages follow_trans_huge_pmd try_grab_folio // warn here To slove this, use local variable page to make notify_page can be seen after finish get_user_pages_fast. Fixes: a1d88436d53a ("VMCI: Fix two UVA mapping bugs") Cc: stable Closes: https://lore.kernel.org/all/e91da589-ad57-3969-d979-879bbd10dddd@huawei.com/ Signed-off-by: Wupeng Ma Link: https://lore.kernel.org/r/20250510033040.901582-1-mawupeng1@huawei.com Signed-off-by: Greg Kroah-Hartman

vmci_host: fix a race condition in vmci_host_poll() causing GPF

2023-04-05T17:37:35Z

During fuzzing, a general protection fault is observed in vmci_host_poll(). general protection fault, probably for non-canonical address 0xdffffc0000000019: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000c8-0x00000000000000cf] RIP: 0010:__lock_acquire+0xf3/0x5e00 kernel/locking/lockdep.c:4926 <- omitting registers -> Call Trace: lock_acquire+0x1a4/0x4a0 kernel/locking/lockdep.c:5672 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:162 add_wait_queue+0x3d/0x260 kernel/sched/wait.c:22 poll_wait include/linux/poll.h:49 [inline] vmci_host_poll+0xf8/0x2b0 drivers/misc/vmw_vmci/vmci_host.c:174 vfs_poll include/linux/poll.h:88 [inline] do_pollfd fs/select.c:873 [inline] do_poll fs/select.c:921 [inline] do_sys_poll+0xc7c/0x1aa0 fs/select.c:1015 __do_sys_ppoll fs/select.c:1121 [inline] __se_sys_ppoll+0x2cc/0x330 fs/select.c:1101 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4e/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Example thread interleaving that causes the general protection fault is as follows: CPU1 (vmci_host_poll) CPU2 (vmci_host_do_init_context) ----- ----- // Read uninitialized context context = vmci_host_dev->context; // Initialize context vmci_host_dev->context = vmci_ctx_create(); vmci_host_dev->ct_type = VMCIOBJ_CONTEXT; if (vmci_host_dev->ct_type == VMCIOBJ_CONTEXT) { // Dereferencing the wrong pointer poll_wait(..., &context->host_context); } In this scenario, vmci_host_poll() reads vmci_host_dev->context first, and then reads vmci_host_dev->ct_type to check that vmci_host_dev->context is initialized. However, since these two reads are not atomically executed, there is a chance of a race condition as described above. To fix this race condition, read vmci_host_dev->context after checking the value of vmci_host_dev->ct_type so that vmci_host_poll() always reads an initialized context. Reported-by: Dae R. Jeong Fixes: 8bf503991f87 ("VMCI: host side driver implementation.") Signed-off-by: Dae R. Jeong Link: https://lore.kernel.org/r/ZCGFsdBAU4cYww5l@dragonet Signed-off-by: Greg Kroah-Hartman

VMCI: check context->notify_page after call to get_user_pages_fast() to avoid GPF

2023-01-20T12:06:10Z

The call to get_user_pages_fast() in vmci_host_setup_notify() can return NULL context->notify_page causing a GPF. To avoid GPF check if context->notify_page == NULL and return error if so. general protection fault, probably for non-canonical address 0xe0009d1000000060: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0x0005088000000300- 0x0005088000000307] CPU: 2 PID: 26180 Comm: repro_34802241 Not tainted 6.1.0-rc4 #1 Hardware name: Red Hat KVM, BIOS 1.15.0-2.module+el8.6.0 04/01/2014 RIP: 0010:vmci_ctx_check_signal_notify+0x91/0xe0 Call Trace: vmci_host_unlocked_ioctl+0x362/0x1f40 __x64_sys_ioctl+0x1a1/0x230 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: a1d88436d53a ("VMCI: Fix two UVA mapping bugs") Reported-by: syzkaller Signed-off-by: George Kennedy Reviewed-by: Vishnu Dasa Link: https://lore.kernel.org/r/1669666705-24012-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Greg Kroah-Hartman

vmci_host: print unexpanded names of ioctl requests in debug messages

2021-03-24T07:26:31Z

__stringify macro function expands its arguments, but in this messages we expect to see ioctl request name instead of it's _IOC macro expansion. $ cat stringify.c #include #include #define __stringify_1(x) #x #define __stringify(x) __stringify_1(x) #define VMCI_DO_IOCTL(ioctl_name) \ char *name = __stringify(IOCTL_VMCI_ ## ioctl_name); int main() { VMCI_DO_IOCTL(INIT_CONTEXT) printf("%s\n", name); } $ cc stringify.c $ ./a.out (((0U) << (((0+8)+8)+14)) | (((7)) << (0+8)) | (((0xa0)) << 0) | ((0) << ((0+8)+8))) Signed-off-by: Gleb Fotengauer-Malinovskiy Link: https://lore.kernel.org/r/20210302153346.300416-1-glebfm@altlinux.org Signed-off-by: Greg Kroah-Hartman

vmci_host: get rid of pointless access_ok()

2020-05-29T15:06:38Z

get_user_pages_fast() doesn't need the caller to check that. NB: reachable only from ioctl(2) and only under USER_DS Reviewed-by: Greg Kroah-Hartman Signed-off-by: Al Viro

Merge tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

2019-12-01T21:46:15Z

Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann: "As part of the cleanup of some remaining y2038 issues, I came to fs/compat_ioctl.c, which still has a couple of commands that need support for time64_t. In completely unrelated work, I spent time on cleaning up parts of this file in the past, moving things out into drivers instead. After Al Viro reviewed an earlier version of this series and did a lot more of that cleanup, I decided to try to completely eliminate the rest of it and move it all into drivers. This series incorporates some of Al's work and many patches of my own, but in the end stops short of actually removing the last part, which is the scsi ioctl handlers. I have patches for those as well, but they need more testing or possibly a rewrite" * tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits) scsi: sd: enable compat ioctls for sed-opal pktcdvd: add compat_ioctl handler compat_ioctl: move SG_GET_REQUEST_TABLE handling compat_ioctl: ppp: move simple commands into ppp_generic.c compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic compat_ioctl: unify copy-in of ppp filters tty: handle compat PPP ioctls compat_ioctl: move SIOCOUTQ out of compat_ioctl.c compat_ioctl: handle SIOCOUTQNSD af_unix: add compat_ioctl support compat_ioctl: reimplement SG_IO handling compat_ioctl: move WDIOC handling into wdt drivers fs: compat_ioctl: move FITRIM emulation into file systems gfs2: add compat_ioctl support compat_ioctl: remove unused convert_in_user macro compat_ioctl: remove last RAID handling code compat_ioctl: remove /dev/raw ioctl translation compat_ioctl: remove PCI ioctl translation compat_ioctl: remove joystick ioctl translation ...

vsock/vmci: register vmci_transport only when VMCI guest/host are active

2019-11-15T02:12:18Z

To allow other transports to be loaded with vmci_transport, we register the vmci_transport as G2H or H2G only when a VMCI guest or host is active. To do that, this patch adds a callback registered in the vmci driver that will be called when the host or guest becomes active. This callback will register the vmci_transport in the VSOCK core. Cc: Jorgen Hansen Signed-off-by: Stefano Garzarella Signed-off-by: David S. Miller

compat_ioctl: move more drivers to compat_ptr_ioctl

2019-10-23T15:23:44Z

The .ioctl and .compat_ioctl file operations have the same prototype so they can both point to the same function, which works great almost all the time when all the commands are compatible. One exception is the s390 architecture, where a compat pointer is only 31 bit wide, and converting it into a 64-bit pointer requires calling compat_ptr(). Most drivers here will never run in s390, but since we now have a generic helper for it, it's easy enough to use it consistently. I double-checked all these drivers to ensure that all ioctl arguments are used as pointers or are ignored, but are not interpreted as integer values. Acked-by: Jason Gunthorpe Acked-by: Daniel Vetter Acked-by: Mauro Carvalho Chehab Acked-by: Greg Kroah-Hartman Acked-by: David Sterba Acked-by: Darren Hart (VMware) Acked-by: Jonathan Cameron Acked-by: Bjorn Andersson Acked-by: Dan Williams Signed-off-by: Arnd Bergmann

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 321

2019-06-05T15:37:05Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 and no later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 33 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Kate Stewart Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000435.345978407@linutronix.de Signed-off-by: Greg Kroah-Hartman

mm/gup: change GUP fast to use flags rather than a write 'bool'

2019-05-14T16:47:46Z

To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com Signed-off-by: Ira Weiny Reviewed-by: Mike Marshall Cc: Aneesh Kumar K.V Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Dan Williams Cc: "David S. Miller" Cc: Heiko Carstens Cc: Ingo Molnar Cc: James Hogan Cc: Jason Gunthorpe Cc: John Hubbard Cc: "Kirill A. Shutemov" Cc: Martin Schwidefsky Cc: Michal Hocko Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Ralf Baechle Cc: Rich Felker Cc: Thomas Gleixner Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds