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[PATCH 01/62] arm, bpf: Fix offset overflow for BPF_MEM BPF_DW
by Yang Yingliang 11 May '20

11 May '20

From: Luke Nelson <lukenels(a)cs.washington.edu> commit 4178417cc5359c329790a4a8f4a6604612338cca upstream. This patch fixes an incorrect check in how immediate memory offsets are computed for BPF_DW on arm. For BPF_LDX/ST/STX + BPF_DW, the 32-bit arm JIT breaks down an 8-byte access into two separate 4-byte accesses using off+0 and off+4. If off fits in imm12, the JIT emits a ldr/str instruction with the immediate and avoids the use of a temporary register. While the current check off <= 0xfff ensures that the first immediate off+0 doesn't overflow imm12, it's not sufficient for the second immediate off+4, which may cause the second access of BPF_DW to read/write the wrong address. This patch fixes the problem by changing the check to off <= 0xfff - 4 for BPF_DW, ensuring off+4 will never overflow. A side effect of simplifying the check is that it now allows using negative immediate offsets in ldr/str. This means that small negative offsets can also avoid the use of a temporary register. This patch introduces no new failures in test_verifier or test_bpf.c. Fixes: c5eae692571d6 ("ARM: net: bpf: improve 64-bit store implementation") Fixes: ec19e02b343db ("ARM: net: bpf: fix LDX instructions") Co-developed-by: Xi Wang <xi.wang(a)gmail.com> Signed-off-by: Xi Wang <xi.wang(a)gmail.com> Signed-off-by: Luke Nelson <luke.r.nels(a)gmail.com> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Link: https://lore.kernel.org/bpf/20200409221752.28448-1-luke.r.nels@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm/net/bpf_jit_32.c | 40 ++++++++++++++++++++++++---------------- 1 file changed, 24 insertions(+), 16 deletions(-) diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 25b3ee8..d06293a 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -993,21 +993,35 @@ static inline void emit_a32_mul_r64(const s8 dst[], const s8 src[], arm_bpf_put_reg32(dst_hi, rd[0], ctx); } +static bool is_ldst_imm(s16 off, const u8 size) +{ + s16 off_max = 0; + + switch (size) { + case BPF_B: + case BPF_W: + off_max = 0xfff; + break; + case BPF_H: + off_max = 0xff; + break; + case BPF_DW: + /* Need to make sure off+4 does not overflow. */ + off_max = 0xfff - 4; + break; + } + return -off_max <= off && off <= off_max; +} + /* *(size *)(dst + off) = src */ static inline void emit_str_r(const s8 dst, const s8 src[], - s32 off, struct jit_ctx *ctx, const u8 sz){ + s16 off, struct jit_ctx *ctx, const u8 sz){ const s8 *tmp = bpf2a32[TMP_REG_1]; - s32 off_max; s8 rd; rd = arm_bpf_get_reg32(dst, tmp[1], ctx); - if (sz == BPF_H) - off_max = 0xff; - else - off_max = 0xfff; - - if (off < 0 || off > off_max) { + if (!is_ldst_imm(off, sz)) { emit_a32_mov_i(tmp[0], off, ctx); emit(ARM_ADD_R(tmp[0], tmp[0], rd), ctx); rd = tmp[0]; @@ -1036,18 +1050,12 @@ static inline void emit_str_r(const s8 dst, const s8 src[], /* dst = *(size*)(src + off) */ static inline void emit_ldx_r(const s8 dst[], const s8 src, - s32 off, struct jit_ctx *ctx, const u8 sz){ + s16 off, struct jit_ctx *ctx, const u8 sz){ const s8 *tmp = bpf2a32[TMP_REG_1]; const s8 *rd = is_stacked(dst_lo) ? tmp : dst; s8 rm = src; - s32 off_max; - - if (sz == BPF_H) - off_max = 0xff; - else - off_max = 0xfff; - if (off < 0 || off > off_max) { + if (!is_ldst_imm(off, sz)) { emit_a32_mov_i(tmp[0], off, ctx); emit(ARM_ADD_R(tmp[0], tmp[0], src), ctx); rm = tmp[0]; -- 1.8.3

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Fwd: kfifo memory ordering analysis
by laokz 11 May '20

11 May '20

openEuler Kernel SIG：你好！内核社区(包括Linus)怀疑kfifo有潜在的BUG，见 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/l… 我于去年底向社区提交了一份分析报告，用litmus验证了问题的可能性，梳理了所有kfifo相关函数和宏，提出了建议。但杳无音信，不知是丢了，还是因无实践 BUG而未受重视。 ARM是典型的弱内存序架构，因此想到转给你们供参考。如无兴趣请忽略:-) 此致 laokz

2 4

[PATCH] net/hinic: Fix TX timeout under ipip tunnel packet
by Yang Yingliang 09 May '20

09 May '20

From: Chiqijun <chiqijun(a)huawei.com> driver inclusion category: bugfix bugzilla: 4472 ----------------------------------------------------------------------- The current driver does not support ipip tunnel packet parsing. When the csum of the device is turned on, driver will get wrong inner headers, and causing device error. Signed-off-by: Chiqijun <chiqijun(a)huawei.com> Reviewed-by: Luoshaokai <luoshaokai(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/net/ethernet/huawei/hinic/hinic_tx.c | 31 ++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/huawei/hinic/hinic_tx.c b/drivers/net/ethernet/huawei/hinic/hinic_tx.c index 05291a5..c8492ae 100644 --- a/drivers/net/ethernet/huawei/hinic/hinic_tx.c +++ b/drivers/net/ethernet/huawei/hinic/hinic_tx.c @@ -373,26 +373,45 @@ static int hinic_tx_csum(struct hinic_sq_task *task, u32 *queue_info, if (ip.v4->version == 4) { l3_type = IPV4_PKT_NO_CHKSUM_OFFLOAD; + l4_proto = ip.v4->protocol; } else if (ip.v4->version == 6) { + unsigned char *exthdr; + __be16 frag_off; + l3_type = IPV6_PKT; #ifdef HAVE_OUTER_IPV6_TUNNEL_OFFLOAD tunnel_type = TUNNEL_UDP_CSUM; #endif + exthdr = ip.hdr + sizeof(*ip.v6); + l4_proto = ip.v6->nexthdr; + l4.hdr = skb_transport_header(skb); + if (l4.hdr != exthdr) + ipv6_skip_exthdr(skb, exthdr - skb->data, + &l4_proto, &frag_off); } else { l3_type = UNKNOWN_L3TYPE; + l4_proto = IPPROTO_RAW; } hinic_task_set_outter_l3(task, l3_type, skb_network_header_len(skb)); - l4_tunnel_len = skb_inner_network_offset(skb) - - skb_transport_offset(skb); + if (l4_proto == IPPROTO_UDP || l4_proto == IPPROTO_GRE) { + l4_tunnel_len = skb_inner_network_offset(skb) - + skb_transport_offset(skb); + ip.hdr = skb_inner_network_header(skb); + l4.hdr = skb_inner_transport_header(skb); + network_hdr_len = skb_inner_network_header_len(skb); + } else { + tunnel_type = NOT_TUNNEL; + l4_tunnel_len = 0; - hinic_task_set_tunnel_l4(task, tunnel_type, l4_tunnel_len); + ip.hdr = skb_inner_network_header(skb); + l4.hdr = skb_transport_header(skb); + network_hdr_len = skb_network_header_len(skb); + } - ip.hdr = skb_inner_network_header(skb); - l4.hdr = skb_inner_transport_header(skb); - network_hdr_len = skb_inner_network_header_len(skb); + hinic_task_set_tunnel_l4(task, tunnel_type, l4_tunnel_len); } else { ip.hdr = skb_network_header(skb); l4.hdr = skb_transport_header(skb); -- 1.8.3

1 0

[PATCH 1/3] USB: core: Fix free-while-in-use bug in the USB S-Glibrary
by Yang Yingliang 09 May '20

09 May '20

From: Alan Stern <stern(a)rowland.harvard.edu> mainline inclusion from mainline-v5.7-rc3 commit 056ad39ee9253873522f6469c3364964a322912b category: bugfix bugzilla: 13690 CVE: CVE-2020-12464 ------------------------------------------------- FuzzUSB (a variant of syzkaller) found a free-while-still-in-use bug in the USB scatter-gather library: BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in usb_hcd_unlink_urb+0x5f/0x170 drivers/usb/core/hcd.c:1607 Read of size 4 at addr ffff888065379610 by task kworker/u4:1/27 CPU: 1 PID: 27 Comm: kworker/u4:1 Not tainted 5.5.11 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Workqueue: scsi_tmf_2 scmd_eh_abort_handler Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xce/0x128 lib/dump_stack.c:118 print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374 __kasan_report+0x153/0x1cb mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:639 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x152/0x1b0 mm/kasan/generic.c:192 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] usb_hcd_unlink_urb+0x5f/0x170 drivers/usb/core/hcd.c:1607 usb_unlink_urb+0x72/0xb0 drivers/usb/core/urb.c:657 usb_sg_cancel+0x14e/0x290 drivers/usb/core/message.c:602 usb_stor_stop_transport+0x5e/0xa0 drivers/usb/storage/transport.c:937 This bug occurs when cancellation of the S-G transfer races with transfer completion. When that happens, usb_sg_cancel() may continue to access the transfer's URBs after usb_sg_wait() has freed them. The bug is caused by the fact that usb_sg_cancel() does not take any sort of reference to the transfer, and so there is nothing to prevent the URBs from being deallocated while the routine is trying to use them. The fix is to take such a reference by incrementing the transfer's io->count field while the cancellation is in progres and decrementing it afterward. The transfer's URBs are not deallocated until io->complete is triggered, which happens when io->count reaches zero. Signed-off-by: Alan Stern <stern(a)rowland.harvard.edu> Reported-and-tested-by: Kyungtae Kim <kt0755(a)gmail.com> CC: <stable(a)vger.kernel.org> Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2003281615140.14837-100000@netrid… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Jason Yan <yanaijie(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/usb/core/message.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 0d3fd20..fcf84bf 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -588,12 +588,13 @@ void usb_sg_cancel(struct usb_sg_request *io) int i, retval; spin_lock_irqsave(&io->lock, flags); - if (io->status) { + if (io->status || io->count == 0) { spin_unlock_irqrestore(&io->lock, flags); return; } /* shut everything down */ io->status = -ECONNRESET; + io->count++; /* Keep the request alive until we're done */ spin_unlock_irqrestore(&io->lock, flags); for (i = io->entries - 1; i >= 0; --i) { @@ -607,6 +608,12 @@ void usb_sg_cancel(struct usb_sg_request *io) dev_warn(&io->dev->dev, "%s, unlink --> %d\n", __func__, retval); } + + spin_lock_irqsave(&io->lock, flags); + io->count--; + if (!io->count) + complete(&io->complete); + spin_unlock_irqrestore(&io->lock, flags); } EXPORT_SYMBOL_GPL(usb_sg_cancel); -- 1.8.3

1 2

[PATCH 1/2] net: hns3: update hns3 version to 1.9.37.9
by Yang Yingliang 09 May '20

09 May '20

From: Shengzui You <youshengzui(a)huawei.com> driver inclusion category: other bugzilla: NA CVE: NA --------------------------------- This patch is used to modify the hns3 driver version to 1.9.37.9 Signed-off-by: Shengzui You <youshengzui(a)huawei.com> Reviewed-by: Weiwei Deng <dengweiwei(a)huawei.com> Reviewed-by: Zhaohui Zhong <zhongzhaohui(a)huawei.com> Reviewed-by: Junxin Chen <chenjunxin1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/net/ethernet/hisilicon/hns3/hnae3.h | 2 +- drivers/net/ethernet/hisilicon/hns3/hns3_cae/hns3_cae_version.h | 2 +- drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 2 +- drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h | 2 +- drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.h | 2 +- 5 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/hisilicon/hns3/hnae3.h b/drivers/net/ethernet/hisilicon/hns3/hnae3.h index 5253374..14b3991 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hnae3.h +++ b/drivers/net/ethernet/hisilicon/hns3/hnae3.h @@ -30,7 +30,7 @@ #include <linux/pci.h> #include <linux/types.h> -#define HNAE3_MOD_VERSION "1.9.37.8" +#define HNAE3_MOD_VERSION "1.9.37.9" #define HNAE3_MIN_VECTOR_NUM 2 /* first one for misc, another for IO */ diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_cae/hns3_cae_version.h b/drivers/net/ethernet/hisilicon/hns3/hns3_cae/hns3_cae_version.h index 34ff097..b89b110 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_cae/hns3_cae_version.h +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_cae/hns3_cae_version.h @@ -4,7 +4,7 @@ #ifndef __HNS3_CAE_VERSION_H__ #define __HNS3_CAE_VERSION_H__ -#define HNS3_CAE_MOD_VERSION "1.9.37.8" +#define HNS3_CAE_MOD_VERSION "1.9.37.9" #define CMT_ID_LEN 8 #define RESV_LEN 3 diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h index 4567c2c..62f34e9 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h @@ -8,7 +8,7 @@ #include "hnae3.h" -#define HNS3_MOD_VERSION "1.9.37.8" +#define HNS3_MOD_VERSION "1.9.37.9" extern char hns3_driver_version[]; diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h index 80270e4..15af034 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h +++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h @@ -12,7 +12,7 @@ #include "hclge_cmd.h" #include "hnae3.h" -#define HCLGE_MOD_VERSION "1.9.37.8" +#define HCLGE_MOD_VERSION "1.9.37.9" #define HCLGE_DRIVER_NAME "hclge" #define HCLGE_MAX_PF_NUM 8 diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.h b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.h index bd24595..f89ee1b 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.h +++ b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.h @@ -10,7 +10,7 @@ #include "hclgevf_cmd.h" #include "hnae3.h" -#define HCLGEVF_MOD_VERSION "1.9.37.8" +#define HCLGEVF_MOD_VERSION "1.9.37.9" #define HCLGEVF_DRIVER_NAME "hclgevf" #define HCLGEVF_MAX_VLAN_ID 4095 -- 1.8.3

1 1

[PATCH] Revert "scsi: fix failing unload of a LLDD module"
by Yang Yingliang 09 May '20

09 May '20

From: Ye Bin <yebin10(a)huawei.com> hulk inclusion category: bugfix bugzilla: 34271 CVE: NA -------------------------------- This reverts commit fd72360bc94ad304136beb56e8ff2ec089113bb8. test setp: ... rmmod hisi_sas_v3_hw lsmod fdisk -l insomd hisi_sas_v3_hw.ko lsmod fdisk -l .... We get follow error when we test by above test steps. [ 3660.259153] [ffff00000116f000] pgd=00002027ffffe003, pud=00002027ffffd003, pmd=00002027cdf28003, pte=0000000000000000 [ 3660.269719] Internal error: Oops: 96000007 [#1] PREEMPT SMP [ 3660.275266] Modules linked in: hisi_sas_v3_hw(+) hisi_sas_main hns_roce_hw_v2(O) hns_roce(O) rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_ipoib ib_umad realtek hns3(O) hclge(O) hnae3(O) crc32_ce crct10dif_ce hisi_hpre hisi_zip hisi_qm uacce hisi_trng_v2 rng_core sfc lbc ip_tables x_tables libsas scsi_transport_sas [last unloaded: hisi_sas_main] [ 3660.308227] Process smartd (pid: 19570, stack limit = 0x000000001103634d) [ 3660.314985] CPU: 31 PID: 19570 Comm: smartd Kdump: loaded Tainted: G O 4.19.36-g32894fc #1 [ 3660.324504] Hardware name: Huawei TaiShan 200 (Model 2280)/BC82AMDD, BIOS 2280-V2 CS V3.B220.02 03/27/2020 [ 3660.334110] pstate: 60400009 (nZCv daif +PAN -UAO) [ 3660.338882] pc : scsi_device_put+0x18/0x38 [ 3660.342961] lr : scsi_disk_put+0x3c/0x58 [ 3660.346865] sp : ffff0000158a3cb0 [ 3660.350164] x29: ffff0000158a3cb0 x28: ffff8027b8111000 [ 3660.355451] x27: 00000000080a005d x26: 0000000000000000 [ 3660.360738] x25: ffff8027c6310398 x24: ffff8027cd2ec410 [ 3660.366025] x23: ffff000009811000 x22: ffff80276d274750 [ 3660.371312] x21: ffff8027abdd5000 x20: ffff8027b8110800 [ 3660.376599] x19: ffff8027abdd5000 x18: 0000000000000000 [ 3660.381886] x17: 0000000000000000 x16: 0000000000000000 [ 3660.387172] x15: 0000000000000000 x14: 0000000000000000 [ 3660.392459] x13: ffff000009996cd0 x12: ffffffffffffffff [ 3660.397746] x11: ffff000009996cc8 x10: 0000000000000000 [ 3660.403033] x9 : 0000000000000000 x8 : 0000000040000000 [ 3660.408320] x7 : ffff0000098116c8 x6 : 0000000000000000 [ 3660.413607] x5 : ffff00000820ebbc x4 : ffff7e009eb8fb20 [ 3660.418894] x3 : 0000000080400009 x2 : ffff8027ae3ec600 [ 3660.424180] x1 : 71b6030ca20bb300 x0 : ffff00000116f000 [ 3660.429467] Call trace: [ 3660.431904] scsi_device_put+0x18/0x38 [ 3660.435636] scsi_disk_put+0x3c/0x58 [ 3660.439195] sd_release+0x50/0xc0 [ 3660.442496] __blkdev_put+0x20c/0x220 [ 3660.446141] blkdev_put+0x4c/0x110 [ 3660.449527] blkdev_close+0x1c/0x28 [ 3660.453000] __fput+0x88/0x1b8 [ 3660.456042] ____fput+0xc/0x18 [ 3660.459085] task_work_run+0x94/0xb0 [ 3660.462646] do_notify_resume+0x17c/0x180 [ 3660.466637] work_pending+0x8/0x10 [ 3660.470022] Code: f9000bf3 aa0003f3 f9400000 f9404c00 (f9400000) [ 3660.476089] ---[ end trace ca1d0144f9241f71 ]--- void scsi_device_put(struct scsi_device *sdev) { module_put(sdev->host->hostt->module); ---> error code put_device(&sdev->sdev_gendev); } When access "sdev->host->hostt" occurs exception, as "sdev->host->hostt" is point to the module address space which is already removed. module_delete first check module reference count, then call module exit function. So after pass module reference count check and before call module exit, we can call scsi_device_get function successfully. As "scsi: fix failing unload of a LLDD module" lead to call scsi_device_get success during remove module. We revert this patch, "scsi: fixup kernel warning during rmmod()" already fixed previous error. Signed-off-by: Ye Bin <yebin10(a)huawei.com> Reviewed-by: Hou Tao <houtao1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/scsi/scsi.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 7d472c2..fc1356d 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -544,6 +544,9 @@ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, * Description: Gets a reference to the scsi_device and increments the use count * of the underlying LLDD module. You must hold host_lock of the * parent Scsi_Host or already have a reference when calling this. + * + * This will fail if a device is deleted or cancelled, or when the LLD module + * is in the process of being unloaded. */ int scsi_device_get(struct scsi_device *sdev) { @@ -551,12 +554,12 @@ int scsi_device_get(struct scsi_device *sdev) goto fail; if (!get_device(&sdev->sdev_gendev)) goto fail; - /* We can fail try_module_get if we're doing SCSI operations - * from module exit (like cache flush) - */ - __module_get(sdev->host->hostt->module); + if (!try_module_get(sdev->host->hostt->module)) + goto fail_put_device; return 0; +fail_put_device: + put_device(&sdev->sdev_gendev); fail: return -ENXIO; } -- 1.8.3

1 0

[PATCH] s390/mm: fix page table upgrade vs 2ndary address mode accesses
by Yang Yingliang 09 May '20

09 May '20

From: Christian Borntraeger <borntraeger(a)de.ibm.com> mainline inclusion from mainline-v5.7-rc4 commit 316ec154810960052d4586b634156c54d0778f74 category: bugfix bugzilla: 13690 CVE: CVE-2020-11884 ------------------------------------------------- A page table upgrade in a kernel section that uses secondary address mode will mess up the kernel instructions as follows: Consider the following scenario: two threads are sharing memory. On CPU1 thread 1 does e.g. strnlen_user(). That gets to old_fs = enable_sacf_uaccess(); len = strnlen_user_srst(src, size); and " la %2,0(%1)\n" " la %3,0(%0,%1)\n" " slgr %0,%0\n" " sacf 256\n" "0: srst %3,%2\n" in strnlen_user_srst(). At that point we are in secondary space mode, control register 1 points to kernel page table and instruction fetching happens via c1, rather than usual c13. Interrupts are not disabled, for obvious reasons. On CPU2 thread 2 does MAP_FIXED mmap(), forcing the upgrade of page table from 3-level to e.g. 4-level one. We'd allocated new top-level table, set it up and now we hit this: notify = 1; spin_unlock_bh(&mm->page_table_lock); } if (notify) on_each_cpu(__crst_table_upgrade, mm, 0); OK, we need to actually change over to use of new page table and we need that to happen in all threads that are currently running. Which happens to include the thread 1. IPI is delivered and we have static void __crst_table_upgrade(void *arg) { struct mm_struct *mm = arg; if (current->active_mm == mm) set_user_asce(mm); __tlb_flush_local(); } run on CPU1. That does static inline void set_user_asce(struct mm_struct *mm) { S390_lowcore.user_asce = mm->context.asce; OK, user page table address updated... __ctl_load(S390_lowcore.user_asce, 1, 1); ... and control register 1 set to it. clear_cpu_flag(CIF_ASCE_PRIMARY); } IPI is run in home space mode, so it's fine - insns are fetched using c13, which always points to kernel page table. But as soon as we return from the interrupt, previous PSW is restored, putting CPU1 back into secondary space mode, at which point we no longer get the kernel instructions from the kernel mapping. The fix is to only fixup the control registers that are currently in use for user processes during the page table update. We must also disable interrupts in enable_sacf_uaccess to synchronize the cr and thread.mm_segment updates against the on_each-cpu. Fixes: 0aaba41b58bc ("s390: remove all code using the access register mode") Cc: stable(a)vger.kernel.org # 4.15+ Reported-by: Al Viro <viro(a)zeniv.linux.org.uk> Reviewed-by: Gerald Schaefer <gerald.schaefer(a)de.ibm.com> References: CVE-2020-11884 Signed-off-by: Christian Borntraeger <borntraeger(a)de.ibm.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Hanjun Guo <guohanjun(a)huawei.com> Reviewed-by: Jason Yan <yanaijie(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- arch/s390/lib/uaccess.c | 4 ++++ arch/s390/mm/pgalloc.c | 16 ++++++++++++++-- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c index c4f8039..0267405 100644 --- a/arch/s390/lib/uaccess.c +++ b/arch/s390/lib/uaccess.c @@ -64,10 +64,13 @@ mm_segment_t enable_sacf_uaccess(void) { mm_segment_t old_fs; unsigned long asce, cr; + unsigned long flags; old_fs = current->thread.mm_segment; if (old_fs & 1) return old_fs; + /* protect against a concurrent page table upgrade */ + local_irq_save(flags); current->thread.mm_segment |= 1; asce = S390_lowcore.kernel_asce; if (likely(old_fs == USER_DS)) { @@ -83,6 +86,7 @@ mm_segment_t enable_sacf_uaccess(void) __ctl_load(asce, 7, 7); set_cpu_flag(CIF_ASCE_SECONDARY); } + local_irq_restore(flags); return old_fs; } EXPORT_SYMBOL(enable_sacf_uaccess); diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c index 814f265..f3bc9c9 100644 --- a/arch/s390/mm/pgalloc.c +++ b/arch/s390/mm/pgalloc.c @@ -72,8 +72,20 @@ static void __crst_table_upgrade(void *arg) { struct mm_struct *mm = arg; - if (current->active_mm == mm) - set_user_asce(mm); + /* we must change all active ASCEs to avoid the creation of new TLBs */ + if (current->active_mm == mm) { + S390_lowcore.user_asce = mm->context.asce; + if (current->thread.mm_segment == USER_DS) { + __ctl_load(S390_lowcore.user_asce, 1, 1); + /* Mark user-ASCE present in CR1 */ + clear_cpu_flag(CIF_ASCE_PRIMARY); + } + if (current->thread.mm_segment == USER_DS_SACF) { + __ctl_load(S390_lowcore.user_asce, 7, 7); + /* enable_sacf_uaccess does all or nothing */ + WARN_ON(!test_cpu_flag(CIF_ASCE_SECONDARY)); + } + } __tlb_flush_local(); } -- 1.8.3

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[PATCH kernel-4.19] kernel: just for testing
by Xie XiuQi 07 May '20

07 May '20

just for testing openeuler kernel ci. Signed-off-by: Xie XiuQi <xiexiuqi(a)huawei.com> --- init/version.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/init/version.c b/init/version.c index ef4012ec4375..b8871517a6b2 100644 --- a/init/version.c +++ b/init/version.c @@ -43,7 +43,7 @@ EXPORT_SYMBOL_GPL(init_uts_ns); /* FIXED STRINGS! Don't touch! */ const char linux_banner[] = - "Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@" + "Linux Version " UTS_RELEASE " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n"; const char linux_proc_banner[] = -- 2.20.1

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[PATCH kernel-4.19] kernel: just for testing
by Xie XiuQi 07 May '20

07 May '20

just for testing openeuler kernel ci. Signed-off-by: Xie XiuQi <xiexiuqi(a)huawei.com> --- init/version.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/init/version.c b/init/version.c index ef4012ec4375..b8871517a6b2 100644 --- a/init/version.c +++ b/init/version.c @@ -43,7 +43,7 @@ EXPORT_SYMBOL_GPL(init_uts_ns); /* FIXED STRINGS! Don't touch! */ const char linux_banner[] = - "Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@" + "Linux Version " UTS_RELEASE " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n"; const char linux_proc_banner[] = -- 2.20.1

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[PATCH 1/3] blk-mq: use static_rqs instead of rqs to iterate tags
by Yang Yingliang 06 May '20

06 May '20

From: yu kuai <yukuai3(a)huawei.com> hulk inclusion category: bugfix bugzilla: 34280 CVE: NA --------------------------- tags->rqs[] will not been cleaned when free driver tag to avoid an extra store on a shared area in the per io path. But there is a window between get driver tag and write tags->rqs[], so we may see stale rq in tags->rqs[] which may have been freed, as the following case: blk_mq_get_request blk_mq_queue_tag_busy_iter -> blk_mq_get_tag -> bt_for_each -> bt_iter -> rq = tags->rqs[] -> rq->q -> blk_mq_rq_ctx_init -> data->hctx->tags->rqs[rq->tag] = rq; In additiion, tags->rqs[] only contains the requests that get driver tag. It is not accurate for io-scheduler case when account busy tags in part_in_flight. To fix both of them, the blk_mq_queue_tag_busy_iter is changed in this patch to use tags->static_rqs[] instead of tags->rqs[]. We have to identify whether there is a io scheduler attached to decide to use hctx->tags or hctx->sched_tags. And we will try to get a non-zero q_usage_counter before that, then could avoid race with update nr_hw_queues, switch io-scheduler and even queue cleanup. Add 'inflight' parameter to determine to iterate in-flight requests or just busy tags and add a new helper interface blk_mq_queue_tag_inflight_iter to iterate all of the in-flight tags and export this interface for drivers. Signed-off-by: yu kuai <yukuai3(a)huawei.com> Reviewed-by: Hou Tao <houtao1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- block/blk-mq-tag.c | 77 ++++++++++++++++++++++++++++++++++++++++---------- block/blk-mq.c | 6 ++-- include/linux/blk-mq.h | 3 +- 3 files changed, 67 insertions(+), 19 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 41317c5..323bbca 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -216,37 +216,51 @@ struct bt_iter_data { busy_iter_fn *fn; void *data; bool reserved; + bool inflight; }; static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) { struct bt_iter_data *iter_data = data; struct blk_mq_hw_ctx *hctx = iter_data->hctx; - struct blk_mq_tags *tags = hctx->tags; bool reserved = iter_data->reserved; + struct blk_mq_tags *tags; struct request *rq; + tags = hctx->sched_tags ? hctx->sched_tags : hctx->tags; + if (!reserved) bitnr += tags->nr_reserved_tags; - rq = tags->rqs[bitnr]; /* - * We can hit rq == NULL here, because the tagging functions - * test and set the bit before assining ->rqs[]. + * Because tags->rqs[] will not been cleaned when free driver tag + * and there is a window between get driver tag and write tags->rqs[], + * so we may see stale rq in tags->rqs[] which may have been freed. + * Using static_rqs[] is safer. */ - if (rq && rq->q == hctx->queue) + rq = tags->static_rqs[bitnr]; + + /* + * There is a small window between get tag and blk_mq_rq_ctx_init, + * so rq->q and rq->mq_hctx maybe different. + */ + if (rq && rq->q == hctx->queue && + (!iter_data->inflight || + blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT)) iter_data->fn(hctx, rq, iter_data->data, reserved); return true; } -static void bt_for_each(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt, - busy_iter_fn *fn, void *data, bool reserved) +static void bt_for_each(struct blk_mq_hw_ctx *hctx, + struct sbitmap_queue *bt, busy_iter_fn *fn, + void *data, bool reserved, bool inflight) { struct bt_iter_data iter_data = { .hctx = hctx, .fn = fn, .data = data, .reserved = reserved, + .inflight = inflight, }; sbitmap_for_each_set(&bt->sb, bt_iter, &iter_data); @@ -314,22 +328,23 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, } EXPORT_SYMBOL(blk_mq_tagset_busy_iter); -void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, - void *priv) +static void __blk_mq_queue_tag_busy_iter(struct request_queue *q, + busy_iter_fn *fn, void *priv, bool inflight) { struct blk_mq_hw_ctx *hctx; int i; /* - * __blk_mq_update_nr_hw_queues will update the nr_hw_queues and - * queue_hw_ctx after freeze the queue, so we use q_usage_counter - * to avoid race with it. + * Get a reference of the queue unless it has been zero. We use this + * to avoid the race with the code that would modify the hctxs after + * freeze and drain the queue, including updating nr_hw_queues, io + * scheduler switching and queue clean up. */ if (!percpu_ref_tryget(&q->q_usage_counter)) return; queue_for_each_hw_ctx(q, hctx, i) { - struct blk_mq_tags *tags = hctx->tags; + struct blk_mq_tags *tags; /* * If not software queues are currently mapped to this @@ -338,13 +353,45 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, if (!blk_mq_hw_queue_mapped(hctx)) continue; + tags = hctx->sched_tags ? hctx->sched_tags : hctx->tags; + if (tags->nr_reserved_tags) - bt_for_each(hctx, &tags->breserved_tags, fn, priv, true); - bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false); + bt_for_each(hctx, &tags->breserved_tags, + fn, priv, true, inflight); + bt_for_each(hctx, &tags->bitmap_tags, + fn, priv, false, inflight); + /* + * flush_rq represents the rq with REQ_PREFLUSH and REQ_FUA + * (if FUA is not supported by device) to be issued to + * device. So we need to consider it when iterate inflight + * rqs, but needn't to count it when iterate busy tags. + */ + if (inflight && + blk_mq_rq_state(hctx->fq->flush_rq) == MQ_RQ_IN_FLIGHT) + fn(hctx, hctx->fq->flush_rq, priv, false); } blk_queue_exit(q); } +/* + * Iterate all the busy tags including pending and in-flight ones. + */ +void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, + void *priv) +{ + __blk_mq_queue_tag_busy_iter(q, fn, priv, false); +} + +/* + * Iterate all the inflight tags. + */ +void blk_mq_queue_tag_inflight_iter(struct request_queue *q, + busy_iter_fn *fn, void *priv) +{ + __blk_mq_queue_tag_busy_iter(q, fn, priv, true); +} +EXPORT_SYMBOL(blk_mq_queue_tag_inflight_iter); + static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, bool round_robin, int node) { diff --git a/block/blk-mq.c b/block/blk-mq.c index 8a7c3d8..ee07575 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -112,7 +112,7 @@ void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part, struct mq_inflight mi = { .part = part, .inflight = inflight, }; inflight[0] = inflight[1] = 0; - blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); + blk_mq_queue_tag_inflight_iter(q, blk_mq_check_inflight, &mi); } static void blk_mq_check_inflight_rw(struct blk_mq_hw_ctx *hctx, @@ -131,7 +131,7 @@ void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, struct mq_inflight mi = { .part = part, .inflight = inflight, }; inflight[0] = inflight[1] = 0; - blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight_rw, &mi); + blk_mq_queue_tag_inflight_iter(q, blk_mq_check_inflight_rw, &mi); } void blk_freeze_queue_start(struct request_queue *q) @@ -875,7 +875,7 @@ static void blk_mq_timeout_work(struct work_struct *work) if (!percpu_ref_tryget(&q->q_usage_counter)) return; - blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &next); + blk_mq_queue_tag_inflight_iter(q, blk_mq_check_expired, &next); if (next != 0) { mod_timer(&q->timeout, next); diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 6578070..149d411 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -320,7 +320,8 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, void blk_mq_freeze_queue_wait(struct request_queue *q); int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, unsigned long timeout); - +void blk_mq_queue_tag_inflight_iter(struct request_queue *q, busy_iter_fn *fn, + void *priv); int blk_mq_map_queues(struct blk_mq_tag_set *set); void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues); -- 1.8.3

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