user/sven/linux.git, branch v5.1.13

Linux 5.1.13

2019-06-22T06:09:16Z

coredump: fix race condition between collapse_huge_page() and core dumping

2019-06-22T06:09:16Z

commit 59ea6d06cfa9247b586a695c21f94afa7183af74 upstream. When fixing the race conditions between the coredump and the mmap_sem holders outside the context of the process, we focused on mmget_not_zero()/get_task_mm() callers in 04f5866e41fb70 ("coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping"), but those aren't the only cases where the mmap_sem can be taken outside of the context of the process as Michal Hocko noticed while backporting that commit to older -stable kernels. If mmgrab() is called in the context of the process, but then the mm_count reference is transferred outside the context of the process, that can also be a problem if the mmap_sem has to be taken for writing through that mm_count reference. khugepaged registration calls mmgrab() in the context of the process, but the mmap_sem for writing is taken later in the context of the khugepaged kernel thread. collapse_huge_page() after taking the mmap_sem for writing doesn't modify any vma, so it's not obvious that it could cause a problem to the coredump, but it happens to modify the pmd in a way that breaks an invariant that pmd_trans_huge_lock() relies upon. collapse_huge_page() needs the mmap_sem for writing just to block concurrent page faults that call pmd_trans_huge_lock(). Specifically the invariant that "!pmd_trans_huge()" cannot become a "pmd_trans_huge()" doesn't hold while collapse_huge_page() runs. The coredump will call __get_user_pages() without mmap_sem for reading, which eventually can invoke a lockless page fault which will need a functional pmd_trans_huge_lock(). So collapse_huge_page() needs to use mmget_still_valid() to check it's not running concurrently with the coredump... as long as the coredump can invoke page faults without holding the mmap_sem for reading. This has "Fixes: khugepaged" to facilitate backporting, but in my view it's more a bug in the coredump code that will eventually have to be rewritten to stop invoking page faults without the mmap_sem for reading. So the long term plan is still to drop all mmget_still_valid(). Link: http://lkml.kernel.org/r/20190607161558.32104-1-aarcange@redhat.com Fixes: ba76149f47d8 ("thp: khugepaged") Signed-off-by: Andrea Arcangeli Reported-by: Michal Hocko Acked-by: Michal Hocko Acked-by: Kirill A. Shutemov Cc: Oleg Nesterov Cc: Jann Horn Cc: Hugh Dickins Cc: Mike Rapoport Cc: Mike Kravetz Cc: Peter Xu Cc: Jason Gunthorpe Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

nvme-tcp: fix queue mapping when queue count is limited

2019-06-22T06:09:16Z

commit 6486199378a505c58fddc47459631235c9fb7638 upstream. When the controller supports less queues than requested, we should make sure that queue mapping does the right thing and not assume that all queues are available. This fixes a crash when the controller supports less queues than requested. The rules are: 1. if no write queues are requested, we assign the available queues to the default queue map. The default and read queue maps share the existing queues. 2. if write queues are requested: - first make sure that read queue map gets the requested nr_io_queues count - then grant the default queue map the minimum between the requested nr_write_queues and the remaining queues. If there are no available queues to dedicate to the default queue map, fallback to (1) and share all the queues in the existing queue map. Also, provide a log indication on how we constructed the different queue maps. Reported-by: Harris, James R Tested-by: Jim Harris Cc: # v5.0+ Suggested-by: Roy Shterman Signed-off-by: Sagi Grimberg Signed-off-by: Greg Kroah-Hartman

nvme-tcp: fix possible null deref on a timed out io queue connect

2019-06-22T06:09:16Z

commit f34e25898a608380a60135288019c4cb6013bec8 upstream. If I/O queue connect times out, we might have freed the queue socket already, so check for that on the error path in nvme_tcp_start_queue. Signed-off-by: Sagi Grimberg Signed-off-by: Christoph Hellwig Signed-off-by: Greg Kroah-Hartman

nvme-tcp: rename function to have nvme_tcp prefix

2019-06-22T06:09:15Z

commit efb973b19b88642bb7e08b8ce8e03b0bbd2a7e2a upstream. usually nvme_ prefix is for core functions. While we're cleaning up, remove redundant empty lines Signed-off-by: Sagi Grimberg Reviewed-by: Minwoo Im Signed-off-by: Christoph Hellwig Signed-off-by: Greg Kroah-Hartman

mm: mmu_gather: remove __tlb_reset_range() for force flush

2019-06-22T06:09:15Z

commit 7a30df49f63ad92318ddf1f7498d1129a77dd4bd upstream. A few new fields were added to mmu_gather to make TLB flush smarter for huge page by telling what level of page table is changed. __tlb_reset_range() is used to reset all these page table state to unchanged, which is called by TLB flush for parallel mapping changes for the same range under non-exclusive lock (i.e. read mmap_sem). Before commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap"), the syscalls (e.g. MADV_DONTNEED, MADV_FREE) which may update PTEs in parallel don't remove page tables. But, the forementioned commit may do munmap() under read mmap_sem and free page tables. This may result in program hang on aarch64 reported by Jan Stancek. The problem could be reproduced by his test program with slightly modified below. ---8<--- static int map_size = 4096; static int num_iter = 500; static long threads_total; static void *distant_area; void *map_write_unmap(void *ptr) { int *fd = ptr; unsigned char *map_address; int i, j = 0; for (i = 0; i < num_iter; i++) { map_address = mmap(distant_area, (size_t) map_size, PROT_WRITE | PROT_READ, MAP_SHARED | MAP_ANONYMOUS, -1, 0); if (map_address == MAP_FAILED) { perror("mmap"); exit(1); } for (j = 0; j < map_size; j++) map_address[j] = 'b'; if (munmap(map_address, map_size) == -1) { perror("munmap"); exit(1); } } return NULL; } void *dummy(void *ptr) { return NULL; } int main(void) { pthread_t thid[2]; /* hint for mmap in map_write_unmap() */ distant_area = mmap(0, DISTANT_MMAP_SIZE, PROT_WRITE | PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); munmap(distant_area, (size_t)DISTANT_MMAP_SIZE); distant_area += DISTANT_MMAP_SIZE / 2; while (1) { pthread_create(&thid[0], NULL, map_write_unmap, NULL); pthread_create(&thid[1], NULL, dummy, NULL); pthread_join(thid[0], NULL); pthread_join(thid[1], NULL); } } ---8<--- The program may bring in parallel execution like below: t1 t2 munmap(map_address) downgrade_write(&mm->mmap_sem); unmap_region() tlb_gather_mmu() inc_tlb_flush_pending(tlb->mm); free_pgtables() tlb->freed_tables = 1 tlb->cleared_pmds = 1 pthread_exit() madvise(thread_stack, 8M, MADV_DONTNEED) zap_page_range() tlb_gather_mmu() inc_tlb_flush_pending(tlb->mm); tlb_finish_mmu() if (mm_tlb_flush_nested(tlb->mm)) __tlb_reset_range() __tlb_reset_range() would reset freed_tables and cleared_* bits, but this may cause inconsistency for munmap() which do free page tables. Then it may result in some architectures, e.g. aarch64, may not flush TLB completely as expected to have stale TLB entries remained. Use fullmm flush since it yields much better performance on aarch64 and non-fullmm doesn't yields significant difference on x86. The original proposed fix came from Jan Stancek who mainly debugged this issue, I just wrapped up everything together. Jan's testing results: v5.2-rc2-24-gbec7550cca10 -------------------------- mean stddev real 37.382 2.780 user 1.420 0.078 sys 54.658 1.855 v5.2-rc2-24-gbec7550cca10 + "mm: mmu_gather: remove __tlb_reset_range() for force flush" ---------------------------------------------------------------------------------------_ mean stddev real 37.119 2.105 user 1.548 0.087 sys 55.698 1.357 [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1558322252-113575-1-git-send-email-yang.shi@linux.alibaba.com Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") Signed-off-by: Yang Shi Signed-off-by: Jan Stancek Reported-by: Jan Stancek Tested-by: Jan Stancek Suggested-by: Will Deacon Tested-by: Will Deacon Acked-by: Will Deacon Cc: Peter Zijlstra Cc: Nick Piggin Cc: "Aneesh Kumar K.V" Cc: Nadav Amit Cc: Minchan Kim Cc: Mel Gorman Cc: [4.20+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ocfs2: fix error path kobject memory leak

2019-06-22T06:09:15Z

[ Upstream commit b9fba67b3806e21b98bd5a98dc3921a8e9b42d61 ] If a call to kobject_init_and_add() fails we should call kobject_put() otherwise we leak memory. Add call to kobject_put() in the error path of call to kobject_init_and_add(). Please note, this has the side effect that the release method is called if kobject_init_and_add() fails. Link: http://lkml.kernel.org/r/20190513033458.2824-1-tobin@kernel.org Signed-off-by: Tobin C. Harding Reviewed-by: Greg Kroah-Hartman Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Gang He Cc: Jun Piao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

mlxsw: spectrum: Prevent force of 56G

2019-06-22T06:09:15Z

[ Upstream commit 275e928f19117d22f6d26dee94548baf4041b773 ] Force of 56G is not supported by hardware in Ethernet devices. This configuration fails with a bad parameter error from firmware. Add check of this case. Instead of trying to set 56G with autoneg off, return a meaningful error. Fixes: 56ade8fe3fe1 ("mlxsw: spectrum: Add initial support for Spectrum ASIC") Signed-off-by: Amit Cohen Acked-by: Jiri Pirko Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

scsi: libsas: delete sas port if expander discover failed

2019-06-22T06:09:15Z

[ Upstream commit 3b0541791453fbe7f42867e310e0c9eb6295364d ] The sas_port(phy->port) allocated in sas_ex_discover_expander() will not be deleted when the expander failed to discover. This will cause resource leak and a further issue of kernel BUG like below: [159785.843156] port-2:17:29: trying to add phy phy-2:17:29 fails: it's already part of another port [159785.852144] ------------[ cut here ]------------ [159785.856833] kernel BUG at drivers/scsi/scsi_transport_sas.c:1086! [159785.863000] Internal error: Oops - BUG: 0 [#1] SMP [159785.867866] CPU: 39 PID: 16993 Comm: kworker/u96:2 Tainted: G W OE 4.19.25-vhulk1901.1.0.h111.aarch64 #1 [159785.878458] Hardware name: Huawei Technologies Co., Ltd. Hi1620EVBCS/Hi1620EVBCS, BIOS Hi1620 CS B070 1P TA 03/21/2019 [159785.889231] Workqueue: 0000:74:02.0_disco_q sas_discover_domain [159785.895224] pstate: 40c00009 (nZcv daif +PAN +UAO) [159785.900094] pc : sas_port_add_phy+0x188/0x1b8 [159785.904524] lr : sas_port_add_phy+0x188/0x1b8 [159785.908952] sp : ffff0001120e3b80 [159785.912341] x29: ffff0001120e3b80 x28: 0000000000000000 [159785.917727] x27: ffff802ade8f5400 x26: ffff0000681b7560 [159785.923111] x25: ffff802adf11a800 x24: ffff0000680e8000 [159785.928496] x23: ffff802ade8f5728 x22: ffff802ade8f5708 [159785.933880] x21: ffff802adea2db40 x20: ffff802ade8f5400 [159785.939264] x19: ffff802adea2d800 x18: 0000000000000010 [159785.944649] x17: 00000000821bf734 x16: ffff00006714faa0 [159785.950033] x15: ffff0000e8ab4ecf x14: 7261702079646165 [159785.955417] x13: 726c612073277469 x12: ffff00006887b830 [159785.960802] x11: ffff00006773eaa0 x10: 7968702079687020 [159785.966186] x9 : 0000000000002453 x8 : 726f702072656874 [159785.971570] x7 : 6f6e6120666f2074 x6 : ffff802bcfb21290 [159785.976955] x5 : ffff802bcfb21290 x4 : 0000000000000000 [159785.982339] x3 : ffff802bcfb298c8 x2 : 337752b234c2ab00 [159785.987723] x1 : 337752b234c2ab00 x0 : 0000000000000000 [159785.993108] Process kworker/u96:2 (pid: 16993, stack limit = 0x0000000072dae094) [159786.000576] Call trace: [159786.003097] sas_port_add_phy+0x188/0x1b8 [159786.007179] sas_ex_get_linkrate.isra.5+0x134/0x140 [159786.012130] sas_ex_discover_expander+0x128/0x408 [159786.016906] sas_ex_discover_dev+0x218/0x4c8 [159786.021249] sas_ex_discover_devices+0x9c/0x1a8 [159786.025852] sas_discover_root_expander+0x134/0x160 [159786.030802] sas_discover_domain+0x1b8/0x1e8 [159786.035148] process_one_work+0x1b4/0x3f8 [159786.039230] worker_thread+0x54/0x470 [159786.042967] kthread+0x134/0x138 [159786.046269] ret_from_fork+0x10/0x18 [159786.049918] Code: 91322300 f0004402 91178042 97fe4c9b (d4210000) [159786.056083] Modules linked in: hns3_enet_ut(OE) hclge(OE) hnae3(OE) hisi_sas_test_hw(OE) hisi_sas_test_main(OE) serdes(OE) [159786.067202] ---[ end trace 03622b9e2d99e196 ]--- [159786.071893] Kernel panic - not syncing: Fatal exception [159786.077190] SMP: stopping secondary CPUs [159786.081192] Kernel Offset: disabled [159786.084753] CPU features: 0x2,a2a00a38 Fixes: 2908d778ab3e ("[SCSI] aic94xx: new driver") Reported-by: Jian Luo Signed-off-by: Jason Yan CC: John Garry Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: scsi_dh_alua: Fix possible null-ptr-deref

2019-06-22T06:09:15Z

[ Upstream commit 12e750bc62044de096ab9a95201213fd912b9994 ] If alloc_workqueue fails in alua_init, it should return -ENOMEM, otherwise it will trigger null-ptr-deref while unloading module which calls destroy_workqueue dereference wq->lock like this: BUG: KASAN: null-ptr-deref in __lock_acquire+0x6b4/0x1ee0 Read of size 8 at addr 0000000000000080 by task syz-executor.0/7045 CPU: 0 PID: 7045 Comm: syz-executor.0 Tainted: G C 5.1.0+ #28 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 Call Trace: dump_stack+0xa9/0x10e __kasan_report+0x171/0x18d ? __lock_acquire+0x6b4/0x1ee0 kasan_report+0xe/0x20 __lock_acquire+0x6b4/0x1ee0 lock_acquire+0xb4/0x1b0 __mutex_lock+0xd8/0xb90 drain_workqueue+0x25/0x290 destroy_workqueue+0x1f/0x3f0 __x64_sys_delete_module+0x244/0x330 do_syscall_64+0x72/0x2a0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Reported-by: Hulk Robot Fixes: 03197b61c5ec ("scsi_dh_alua: Use workqueue for RTPG") Signed-off-by: YueHaibing Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin