kernel, branch linux-5.2.y

Linux 5.2.21

2019-10-11T16:22:37Z

Linux 5.2.20

2019-10-07T16:59:42Z

vfs: set fs_context::user_ns for reconfigure

2019-10-07T16:59:42Z

commit 1dd9bc08cf1420d466dd8dcfcc233777e61ca5d2 upstream. fs_context::user_ns is used by fuse_parse_param(), even during remount, so it needs to be set to the existing value for reconfigure. Reproducer: #include #include int main() { char opts[128]; int fd = open("/dev/fuse", O_RDWR); sprintf(opts, "fd=%d,rootmode=040000,user_id=0,group_id=0", fd); mkdir("mnt", 0777); mount("foo", "mnt", "fuse.foo", 0, opts); mount("foo", "mnt", "fuse.foo", MS_REMOUNT, opts); } Crash: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 0 PID: 129 Comm: syz_make_kuid Not tainted 5.3.0-rc5-next-20190821 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014 RIP: 0010:map_id_range_down+0xb/0xc0 kernel/user_namespace.c:291 [...] Call Trace: map_id_down kernel/user_namespace.c:312 [inline] make_kuid+0xe/0x10 kernel/user_namespace.c:389 fuse_parse_param+0x116/0x210 fs/fuse/inode.c:523 vfs_parse_fs_param+0xdb/0x1b0 fs/fs_context.c:145 vfs_parse_fs_string+0x6a/0xa0 fs/fs_context.c:188 generic_parse_monolithic+0x85/0xc0 fs/fs_context.c:228 parse_monolithic_mount_data+0x1b/0x20 fs/fs_context.c:708 do_remount fs/namespace.c:2525 [inline] do_mount+0x39a/0xa60 fs/namespace.c:3107 ksys_mount+0x7d/0xd0 fs/namespace.c:3325 __do_sys_mount fs/namespace.c:3339 [inline] __se_sys_mount fs/namespace.c:3336 [inline] __x64_sys_mount+0x20/0x30 fs/namespace.c:3336 do_syscall_64+0x4a/0x1a0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Reported-by: syzbot+7d6a57304857423318a5@syzkaller.appspotmail.com Fixes: 408cbe695350 ("vfs: Convert fuse to use the new mount API") Cc: David Howells Cc: Miklos Szeredi Signed-off-by: Eric Biggers Reviewed-by: David Howells Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

9p/cache.c: Fix memory leak in v9fs_cache_session_get_cookie

2019-10-07T16:59:41Z

commit 962a991c5de18452d6c429d99f3039387cf5cbb0 upstream. v9fs_cache_session_get_cookie assigns a random cachetag to v9ses->cachetag, if the cachetag is not assigned previously. v9fs_random_cachetag allocates memory to v9ses->cachetag with kmalloc and uses scnprintf to fill it up with a cachetag. But if scnprintf fails, v9ses->cachetag is not freed in the current code causing a memory leak. Fix this by freeing v9ses->cachetag it v9fs_random_cachetag fails. This was reported by syzbot, the link to the report is below: https://syzkaller.appspot.com/bug?id=f012bdf297a7a4c860c38a88b44fbee43fd9bbf3 Link: http://lkml.kernel.org/r/20190522194519.GA5313@bharath12345-Inspiron-5559 Reported-by: syzbot+3a030a73b6c1e9833815@syzkaller.appspotmail.com Signed-off-by: Bharath Vedartham Signed-off-by: Dominique Martinet Signed-off-by: Greg Kroah-Hartman

KVM: hyperv: Fix Direct Synthetic timers assert an interrupt w/o lapic_in_kernel

2019-10-07T16:59:41Z

commit a073d7e3ad687a7ef32b65affe80faa7ce89bf92 upstream. Reported by syzkaller: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:__apic_accept_irq+0x46/0x740 arch/x86/kvm/lapic.c:1029 Call Trace: kvm_apic_set_irq+0xb4/0x140 arch/x86/kvm/lapic.c:558 stimer_notify_direct arch/x86/kvm/hyperv.c:648 [inline] stimer_expiration arch/x86/kvm/hyperv.c:659 [inline] kvm_hv_process_stimers+0x594/0x1650 arch/x86/kvm/hyperv.c:686 vcpu_enter_guest+0x2b2a/0x54b0 arch/x86/kvm/x86.c:7896 vcpu_run+0x393/0xd40 arch/x86/kvm/x86.c:8152 kvm_arch_vcpu_ioctl_run+0x636/0x900 arch/x86/kvm/x86.c:8360 kvm_vcpu_ioctl+0x6cf/0xaf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2765 The testcase programs HV_X64_MSR_STIMERn_CONFIG/HV_X64_MSR_STIMERn_COUNT, in addition, there is no lapic in the kernel, the counters value are small enough in order that kvm_hv_process_stimers() inject this already-expired timer interrupt into the guest through lapic in the kernel which triggers the NULL deferencing. This patch fixes it by don't advertise direct mode synthetic timers and discarding the inject when lapic is not in kernel. syzkaller source: https://syzkaller.appspot.com/x/repro.c?x=1752fe0a600000 Reported-by: syzbot+dff25ee91f0c7d5c1695@syzkaller.appspotmail.com Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li Reviewed-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

kexec: bail out upon SIGKILL when allocating memory.

2019-10-07T16:59:40Z

commit 7c3a6aedcd6aae0a32a527e68669f7dd667492d1 upstream. syzbot found that a thread can stall for minutes inside kexec_load() after that thread was killed by SIGKILL [1]. It turned out that the reproducer was trying to allocate 2408MB of memory using kimage_alloc_page() from kimage_load_normal_segment(). Let's check for SIGKILL before doing memory allocation. [1] https://syzkaller.appspot.com/bug?id=a0e3436829698d5824231251fad9d8e998f94f5e Link: http://lkml.kernel.org/r/993c9185-d324-2640-d061-bed2dd18b1f7@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa Reported-by: syzbot Cc: Eric Biederman Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

NFC: fix attrs checks in netlink interface

2019-10-07T16:59:40Z

commit 18917d51472fe3b126a3a8f756c6b18085eb8130 upstream. nfc_genl_deactivate_target() relies on the NFC_ATTR_TARGET_INDEX attribute being present, but doesn't check whether it is actually provided by the user. Same goes for nfc_genl_fw_download() and NFC_ATTR_FIRMWARE_NAME. This patch adds appropriate checks. Found with syzkaller. Signed-off-by: Andrey Konovalov Signed-off-by: Andy Shevchenko Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

dm raid: fix updating of max_discard_sectors limit

2019-10-07T16:59:40Z

commit c8156fc77d0796ba2618936dbb3084e769e916c1 upstream. Unit of 'chunk_size' is byte, instead of sector, so fix it by setting the queue_limits' max_discard_sectors to rs->md.chunk_sectors. Also, rename chunk_size to chunk_size_bytes. Without this fix, too big max_discard_sectors is applied on the request queue of dm-raid, finally raid code has to split the bio again. This re-split done by raid causes the following nested clone_endio: 1) one big bio 'A' is submitted to dm queue, and served as the original bio 2) one new bio 'B' is cloned from the original bio 'A', and .map() is run on this bio of 'B', and B's original bio points to 'A' 3) raid code sees that 'B' is too big, and split 'B' and re-submit the remainded part of 'B' to dm-raid queue via generic_make_request(). 4) now dm will handle 'B' as new original bio, then allocate a new clone bio of 'C' and run .map() on 'C'. Meantime C's original bio points to 'B'. 5) suppose now 'C' is completed by raid directly, then the following clone_endio() is called recursively: clone_endio(C) ->clone_endio(B) #B is original bio of 'C' ->bio_endio(A) 'A' can be big enough to make hundreds of nested clone_endio(), then stack can be corrupted easily. Fixes: 61697a6abd24a ("dm: eliminate 'split_discard_bios' flag from DM target interface") Cc: stable@vger.kernel.org Signed-off-by: Ming Lei Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

smack: use GFP_NOFS while holding inode_smack::smk_lock

2019-10-07T16:59:40Z

commit e5bfad3d7acc5702f32aafeb388362994f4d7bd0 upstream. inode_smack::smk_lock is taken during smack_d_instantiate(), which is called during a filesystem transaction when creating a file on ext4. Therefore to avoid a deadlock, all code that takes this lock must use GFP_NOFS, to prevent memory reclaim from waiting for the filesystem transaction to complete. Reported-by: syzbot+0eefc1e06a77d327a056@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman

Smack: Don't ignore other bprm->unsafe flags if LSM_UNSAFE_PTRACE is set

2019-10-07T16:59:39Z

commit 3675f052b43ba51b99b85b073c7070e083f3e6fb upstream. There is a logic bug in the current smack_bprm_set_creds(): If LSM_UNSAFE_PTRACE is set, but the ptrace state is deemed to be acceptable (e.g. because the ptracer detached in the meantime), the other ->unsafe flags aren't checked. As far as I can tell, this means that something like the following could work (but I haven't tested it): - task A: create task B with fork() - task B: set NO_NEW_PRIVS - task B: install a seccomp filter that makes open() return 0 under some conditions - task B: replace fd 0 with a malicious library - task A: attach to task B with PTRACE_ATTACH - task B: execve() a file with an SMACK64EXEC extended attribute - task A: while task B is still in the middle of execve(), exit (which destroys the ptrace relationship) Make sure that if any flags other than LSM_UNSAFE_PTRACE are set in bprm->unsafe, we reject the execve(). Cc: stable@vger.kernel.org Fixes: 5663884caab1 ("Smack: unify all ptrace accesses in the smack") Signed-off-by: Jann Horn Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman