* [PATCH] serial: 8250: fix null-ptr-deref in serial8250_start_tx() @ 2020-07-21 14:38 Yang Yingliang 2020-07-21 10:48 ` Greg KH 2020-07-22 1:56 ` liwei (GF) 0 siblings, 2 replies; 6+ messages in thread From: Yang Yingliang @ 2020-07-21 14:38 UTC (permalink / raw) To: linux-serial, linux-kernel; +Cc: gregkh, jslaby, yangyingliang I got null-ptr-deref in serial8250_start_tx(): [ 78.114630] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 78.123778] Mem abort info: [ 78.126560] ESR = 0x86000007 [ 78.129603] EC = 0x21: IABT (current EL), IL = 32 bits [ 78.134891] SET = 0, FnV = 0 [ 78.137933] EA = 0, S1PTW = 0 [ 78.141064] user pgtable: 64k pages, 48-bit VAs, pgdp=00000027d41a8600 [ 78.147562] [0000000000000000] pgd=00000027893f0003, p4d=00000027893f0003, pud=00000027893f0003, pmd=00000027c9a20003, pte=0000000000000000 [ 78.160029] Internal error: Oops: 86000007 [#1] SMP [ 78.164886] Modules linked in: sunrpc vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce ses enclosure sg sbsa_gwdt ipmi_ssif spi_dw_mmio sch_fq_codel vhost_net tun vhost vhost_iotlb tap ip_tables ext4 mbcache jbd2 ahci hisi_sas_v3_hw libahci hisi_sas_main libsas hns3 scsi_transport_sas hclge libata megaraid_sas ipmi_si hnae3 ipmi_devintf ipmi_msghandler br_netfilter bridge stp llc nvme nvme_core xt_sctp sctp libcrc32c dm_mod nbd [ 78.207383] CPU: 11 PID: 23258 Comm: null-ptr Not tainted 5.8.0-rc6+ #48 [ 78.214056] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B210.01 03/12/2020 [ 78.222888] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--) [ 78.228435] pc : 0x0 [ 78.230618] lr : serial8250_start_tx+0x160/0x260 [ 78.235215] sp : ffff800062eefb80 [ 78.238517] x29: ffff800062eefb80 x28: 0000000000000fff [ 78.243807] x27: ffff800062eefd80 x26: ffff202fd83b3000 [ 78.249098] x25: ffff800062eefd80 x24: ffff202fd83b3000 [ 78.254388] x23: ffff002fc5e50be8 x22: 0000000000000002 [ 78.259679] x21: 0000000000000001 x20: 0000000000000000 [ 78.264969] x19: ffffa688827eecc8 x18: 0000000000000000 [ 78.270259] x17: 0000000000000000 x16: 0000000000000000 [ 78.275550] x15: ffffa68881bc67a8 x14: 00000000000002e6 [ 78.280841] x13: ffffa68881bc67a8 x12: 000000000000c539 [ 78.286131] x11: d37a6f4de9bd37a7 x10: ffffa68881cccff0 [ 78.291421] x9 : ffffa68881bc6000 x8 : ffffa688819daa88 [ 78.296711] x7 : ffffa688822a0f20 x6 : ffffa688819e0000 [ 78.302002] x5 : ffff800062eef9d0 x4 : ffffa68881e707a8 [ 78.307292] x3 : 0000000000000000 x2 : 0000000000000002 [ 78.312582] x1 : 0000000000000001 x0 : ffffa688827eecc8 [ 78.317873] Call trace: [ 78.320312] 0x0 [ 78.322147] __uart_start.isra.9+0x64/0x78 [ 78.326229] uart_start+0xb8/0x1c8 [ 78.329620] uart_flush_chars+0x24/0x30 [ 78.333442] n_tty_receive_buf_common+0x7b0/0xc30 [ 78.338128] n_tty_receive_buf+0x44/0x2c8 [ 78.342122] tty_ioctl+0x348/0x11f8 [ 78.345599] ksys_ioctl+0xd8/0xf8 [ 78.348903] __arm64_sys_ioctl+0x2c/0xc8 [ 78.352812] el0_svc_common.constprop.2+0x88/0x1b0 [ 78.357583] do_el0_svc+0x44/0xd0 [ 78.360887] el0_sync_handler+0x14c/0x1d0 [ 78.364880] el0_sync+0x140/0x180 [ 78.368185] Code: bad PC value SERIAL_PORT_DFNS is not defined on each arch, if it's not defined, serial8250_set_defaults() won't be called in serial8250_isa_init_ports(), so the p->serial_in pointer won't be initialized, and it leads a null-ptr-deref. Fix this problem by calling serial8250_set_defaults() after init uart port. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/tty/serial/8250/8250_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index fc118f649887..cae61d1ebec5 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -524,6 +524,7 @@ static void __init serial8250_isa_init_ports(void) */ up->mcr_mask = ~ALPHA_KLUDGE_MCR; up->mcr_force = ALPHA_KLUDGE_MCR; + serial8250_set_defaults(up); } /* chain base port ops to support Remote Supervisor Adapter */ @@ -547,7 +548,6 @@ static void __init serial8250_isa_init_ports(void) port->membase = old_serial_port[i].iomem_base; port->iotype = old_serial_port[i].io_type; port->regshift = old_serial_port[i].iomem_reg_shift; - serial8250_set_defaults(up); port->irqflags |= irqflag; if (serial8250_isa_config != NULL) -- 2.25.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] serial: 8250: fix null-ptr-deref in serial8250_start_tx() 2020-07-21 14:38 [PATCH] serial: 8250: fix null-ptr-deref in serial8250_start_tx() Yang Yingliang @ 2020-07-21 10:48 ` Greg KH 2020-07-21 11:54 ` Yang Yingliang 2020-07-22 1:56 ` liwei (GF) 1 sibling, 1 reply; 6+ messages in thread From: Greg KH @ 2020-07-21 10:48 UTC (permalink / raw) To: Yang Yingliang; +Cc: linux-serial, linux-kernel, jslaby On Tue, Jul 21, 2020 at 02:38:52PM +0000, Yang Yingliang wrote: > I got null-ptr-deref in serial8250_start_tx(): > > [ 78.114630] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 > [ 78.123778] Mem abort info: > [ 78.126560] ESR = 0x86000007 > [ 78.129603] EC = 0x21: IABT (current EL), IL = 32 bits > [ 78.134891] SET = 0, FnV = 0 > [ 78.137933] EA = 0, S1PTW = 0 > [ 78.141064] user pgtable: 64k pages, 48-bit VAs, pgdp=00000027d41a8600 > [ 78.147562] [0000000000000000] pgd=00000027893f0003, p4d=00000027893f0003, pud=00000027893f0003, pmd=00000027c9a20003, pte=0000000000000000 > [ 78.160029] Internal error: Oops: 86000007 [#1] SMP > [ 78.164886] Modules linked in: sunrpc vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce ses enclosure sg sbsa_gwdt ipmi_ssif spi_dw_mmio sch_fq_codel vhost_net tun vhost vhost_iotlb tap ip_tables ext4 mbcache jbd2 ahci hisi_sas_v3_hw libahci hisi_sas_main libsas hns3 scsi_transport_sas hclge libata megaraid_sas ipmi_si hnae3 ipmi_devintf ipmi_msghandler br_netfilter bridge stp llc nvme nvme_core xt_sctp sctp libcrc32c dm_mod nbd > [ 78.207383] CPU: 11 PID: 23258 Comm: null-ptr Not tainted 5.8.0-rc6+ #48 > [ 78.214056] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B210.01 03/12/2020 > [ 78.222888] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--) > [ 78.228435] pc : 0x0 > [ 78.230618] lr : serial8250_start_tx+0x160/0x260 > [ 78.235215] sp : ffff800062eefb80 > [ 78.238517] x29: ffff800062eefb80 x28: 0000000000000fff > [ 78.243807] x27: ffff800062eefd80 x26: ffff202fd83b3000 > [ 78.249098] x25: ffff800062eefd80 x24: ffff202fd83b3000 > [ 78.254388] x23: ffff002fc5e50be8 x22: 0000000000000002 > [ 78.259679] x21: 0000000000000001 x20: 0000000000000000 > [ 78.264969] x19: ffffa688827eecc8 x18: 0000000000000000 > [ 78.270259] x17: 0000000000000000 x16: 0000000000000000 > [ 78.275550] x15: ffffa68881bc67a8 x14: 00000000000002e6 > [ 78.280841] x13: ffffa68881bc67a8 x12: 000000000000c539 > [ 78.286131] x11: d37a6f4de9bd37a7 x10: ffffa68881cccff0 > [ 78.291421] x9 : ffffa68881bc6000 x8 : ffffa688819daa88 > [ 78.296711] x7 : ffffa688822a0f20 x6 : ffffa688819e0000 > [ 78.302002] x5 : ffff800062eef9d0 x4 : ffffa68881e707a8 > [ 78.307292] x3 : 0000000000000000 x2 : 0000000000000002 > [ 78.312582] x1 : 0000000000000001 x0 : ffffa688827eecc8 > [ 78.317873] Call trace: > [ 78.320312] 0x0 > [ 78.322147] __uart_start.isra.9+0x64/0x78 > [ 78.326229] uart_start+0xb8/0x1c8 > [ 78.329620] uart_flush_chars+0x24/0x30 > [ 78.333442] n_tty_receive_buf_common+0x7b0/0xc30 > [ 78.338128] n_tty_receive_buf+0x44/0x2c8 > [ 78.342122] tty_ioctl+0x348/0x11f8 > [ 78.345599] ksys_ioctl+0xd8/0xf8 > [ 78.348903] __arm64_sys_ioctl+0x2c/0xc8 > [ 78.352812] el0_svc_common.constprop.2+0x88/0x1b0 > [ 78.357583] do_el0_svc+0x44/0xd0 > [ 78.360887] el0_sync_handler+0x14c/0x1d0 > [ 78.364880] el0_sync+0x140/0x180 > [ 78.368185] Code: bad PC value > > SERIAL_PORT_DFNS is not defined on each arch, if it's not defined, > serial8250_set_defaults() won't be called in serial8250_isa_init_ports(), > so the p->serial_in pointer won't be initialized, and it leads a null-ptr-deref. > Fix this problem by calling serial8250_set_defaults() after init uart port. > > Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> > --- > drivers/tty/serial/8250/8250_core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Does this fix a specific commit, or has this issue always been present? What has caused it to happen now that no one else has seen this? thanks, greg k-h ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] serial: 8250: fix null-ptr-deref in serial8250_start_tx() 2020-07-21 10:48 ` Greg KH @ 2020-07-21 11:54 ` Yang Yingliang 2020-07-21 12:18 ` Yang Yingliang 0 siblings, 1 reply; 6+ messages in thread From: Yang Yingliang @ 2020-07-21 11:54 UTC (permalink / raw) To: Greg KH; +Cc: linux-serial, linux-kernel, jslaby, Hanjun Guo, Libin (Huawei) On 2020/7/21 18:48, Greg KH wrote: > On Tue, Jul 21, 2020 at 02:38:52PM +0000, Yang Yingliang wrote: >> I got null-ptr-deref in serial8250_start_tx(): >> >> [ 78.114630] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 >> [ 78.123778] Mem abort info: >> [ 78.126560] ESR = 0x86000007 >> [ 78.129603] EC = 0x21: IABT (current EL), IL = 32 bits >> [ 78.134891] SET = 0, FnV = 0 >> [ 78.137933] EA = 0, S1PTW = 0 >> [ 78.141064] user pgtable: 64k pages, 48-bit VAs, pgdp=00000027d41a8600 >> [ 78.147562] [0000000000000000] pgd=00000027893f0003, p4d=00000027893f0003, pud=00000027893f0003, pmd=00000027c9a20003, pte=0000000000000000 >> [ 78.160029] Internal error: Oops: 86000007 [#1] SMP >> [ 78.164886] Modules linked in: sunrpc vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce ses enclosure sg sbsa_gwdt ipmi_ssif spi_dw_mmio sch_fq_codel vhost_net tun vhost vhost_iotlb tap ip_tables ext4 mbcache jbd2 ahci hisi_sas_v3_hw libahci hisi_sas_main libsas hns3 scsi_transport_sas hclge libata megaraid_sas ipmi_si hnae3 ipmi_devintf ipmi_msghandler br_netfilter bridge stp llc nvme nvme_core xt_sctp sctp libcrc32c dm_mod nbd >> [ 78.207383] CPU: 11 PID: 23258 Comm: null-ptr Not tainted 5.8.0-rc6+ #48 >> [ 78.214056] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B210.01 03/12/2020 >> [ 78.222888] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--) >> [ 78.228435] pc : 0x0 >> [ 78.230618] lr : serial8250_start_tx+0x160/0x260 >> [ 78.235215] sp : ffff800062eefb80 >> [ 78.238517] x29: ffff800062eefb80 x28: 0000000000000fff >> [ 78.243807] x27: ffff800062eefd80 x26: ffff202fd83b3000 >> [ 78.249098] x25: ffff800062eefd80 x24: ffff202fd83b3000 >> [ 78.254388] x23: ffff002fc5e50be8 x22: 0000000000000002 >> [ 78.259679] x21: 0000000000000001 x20: 0000000000000000 >> [ 78.264969] x19: ffffa688827eecc8 x18: 0000000000000000 >> [ 78.270259] x17: 0000000000000000 x16: 0000000000000000 >> [ 78.275550] x15: ffffa68881bc67a8 x14: 00000000000002e6 >> [ 78.280841] x13: ffffa68881bc67a8 x12: 000000000000c539 >> [ 78.286131] x11: d37a6f4de9bd37a7 x10: ffffa68881cccff0 >> [ 78.291421] x9 : ffffa68881bc6000 x8 : ffffa688819daa88 >> [ 78.296711] x7 : ffffa688822a0f20 x6 : ffffa688819e0000 >> [ 78.302002] x5 : ffff800062eef9d0 x4 : ffffa68881e707a8 >> [ 78.307292] x3 : 0000000000000000 x2 : 0000000000000002 >> [ 78.312582] x1 : 0000000000000001 x0 : ffffa688827eecc8 >> [ 78.317873] Call trace: >> [ 78.320312] 0x0 >> [ 78.322147] __uart_start.isra.9+0x64/0x78 >> [ 78.326229] uart_start+0xb8/0x1c8 >> [ 78.329620] uart_flush_chars+0x24/0x30 >> [ 78.333442] n_tty_receive_buf_common+0x7b0/0xc30 >> [ 78.338128] n_tty_receive_buf+0x44/0x2c8 >> [ 78.342122] tty_ioctl+0x348/0x11f8 >> [ 78.345599] ksys_ioctl+0xd8/0xf8 >> [ 78.348903] __arm64_sys_ioctl+0x2c/0xc8 >> [ 78.352812] el0_svc_common.constprop.2+0x88/0x1b0 >> [ 78.357583] do_el0_svc+0x44/0xd0 >> [ 78.360887] el0_sync_handler+0x14c/0x1d0 >> [ 78.364880] el0_sync+0x140/0x180 >> [ 78.368185] Code: bad PC value >> >> SERIAL_PORT_DFNS is not defined on each arch, if it's not defined, >> serial8250_set_defaults() won't be called in serial8250_isa_init_ports(), >> so the p->serial_in pointer won't be initialized, and it leads a null-ptr-deref. >> Fix this problem by calling serial8250_set_defaults() after init uart port. >> >> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> >> --- >> drivers/tty/serial/8250/8250_core.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) > Does this fix a specific commit, or has this issue always been present? > What has caused it to happen now that no one else has seen this? I think it's always been present on the arch that not defined SERIAL_PORT_DFNS. I got this on arm64 and here is the C reproducer: // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include <endian.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/syscall.h> #include <sys/types.h> #include <unistd.h> #ifndef __NR_ioctl #define __NR_ioctl 29 #endif #ifndef __NR_mmap #define __NR_mmap 222 #endif #ifndef __NR_openat #define __NR_openat 56 #endif uint64_t r[1] = {0xffffffffffffffff}; int main(void) { syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0); intptr_t res = 0; memcpy((void*)0x20000040, "/dev/ttyS3\000", 11); res = syscall(__NR_openat, 0xffffffffffffff9cul, 0x20000040ul, 0x401ul, 0ul); if (res != -1) r[0] = res; syscall(__NR_ioctl, r[0], 0x5412ul, 0x20000080ul); return 0; } Thanks, Yang > > thanks, > > greg k-h > . ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] serial: 8250: fix null-ptr-deref in serial8250_start_tx() 2020-07-21 11:54 ` Yang Yingliang @ 2020-07-21 12:18 ` Yang Yingliang 2020-07-21 19:11 ` Greg KH 0 siblings, 1 reply; 6+ messages in thread From: Yang Yingliang @ 2020-07-21 12:18 UTC (permalink / raw) To: Greg KH; +Cc: linux-serial, linux-kernel, jslaby, Hanjun Guo, Libin (Huawei) On 2020/7/21 19:54, Yang Yingliang wrote: > > On 2020/7/21 18:48, Greg KH wrote: >> On Tue, Jul 21, 2020 at 02:38:52PM +0000, Yang Yingliang wrote: >>> I got null-ptr-deref in serial8250_start_tx(): >>> >>> [ 78.114630] Unable to handle kernel NULL pointer dereference at >>> virtual address 0000000000000000 >>> [ 78.123778] Mem abort info: >>> [ 78.126560] ESR = 0x86000007 >>> [ 78.129603] EC = 0x21: IABT (current EL), IL = 32 bits >>> [ 78.134891] SET = 0, FnV = 0 >>> [ 78.137933] EA = 0, S1PTW = 0 >>> [ 78.141064] user pgtable: 64k pages, 48-bit VAs, >>> pgdp=00000027d41a8600 >>> [ 78.147562] [0000000000000000] pgd=00000027893f0003, >>> p4d=00000027893f0003, pud=00000027893f0003, pmd=00000027c9a20003, >>> pte=0000000000000000 >>> [ 78.160029] Internal error: Oops: 86000007 [#1] SMP >>> [ 78.164886] Modules linked in: sunrpc vfat fat aes_ce_blk >>> crypto_simd cryptd aes_ce_cipher crct10dif_ce ghash_ce sha2_ce >>> sha256_arm64 sha1_ce ses enclosure sg sbsa_gwdt ipmi_ssif >>> spi_dw_mmio sch_fq_codel vhost_net tun vhost vhost_iotlb tap >>> ip_tables ext4 mbcache jbd2 ahci hisi_sas_v3_hw libahci >>> hisi_sas_main libsas hns3 scsi_transport_sas hclge libata >>> megaraid_sas ipmi_si hnae3 ipmi_devintf ipmi_msghandler br_netfilter >>> bridge stp llc nvme nvme_core xt_sctp sctp libcrc32c dm_mod nbd >>> [ 78.207383] CPU: 11 PID: 23258 Comm: null-ptr Not tainted >>> 5.8.0-rc6+ #48 >>> [ 78.214056] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS >>> 2280-V2 CS V3.B210.01 03/12/2020 >>> [ 78.222888] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--) >>> [ 78.228435] pc : 0x0 >>> [ 78.230618] lr : serial8250_start_tx+0x160/0x260 >>> [ 78.235215] sp : ffff800062eefb80 >>> [ 78.238517] x29: ffff800062eefb80 x28: 0000000000000fff >>> [ 78.243807] x27: ffff800062eefd80 x26: ffff202fd83b3000 >>> [ 78.249098] x25: ffff800062eefd80 x24: ffff202fd83b3000 >>> [ 78.254388] x23: ffff002fc5e50be8 x22: 0000000000000002 >>> [ 78.259679] x21: 0000000000000001 x20: 0000000000000000 >>> [ 78.264969] x19: ffffa688827eecc8 x18: 0000000000000000 >>> [ 78.270259] x17: 0000000000000000 x16: 0000000000000000 >>> [ 78.275550] x15: ffffa68881bc67a8 x14: 00000000000002e6 >>> [ 78.280841] x13: ffffa68881bc67a8 x12: 000000000000c539 >>> [ 78.286131] x11: d37a6f4de9bd37a7 x10: ffffa68881cccff0 >>> [ 78.291421] x9 : ffffa68881bc6000 x8 : ffffa688819daa88 >>> [ 78.296711] x7 : ffffa688822a0f20 x6 : ffffa688819e0000 >>> [ 78.302002] x5 : ffff800062eef9d0 x4 : ffffa68881e707a8 >>> [ 78.307292] x3 : 0000000000000000 x2 : 0000000000000002 >>> [ 78.312582] x1 : 0000000000000001 x0 : ffffa688827eecc8 >>> [ 78.317873] Call trace: >>> [ 78.320312] 0x0 >>> [ 78.322147] __uart_start.isra.9+0x64/0x78 >>> [ 78.326229] uart_start+0xb8/0x1c8 >>> [ 78.329620] uart_flush_chars+0x24/0x30 >>> [ 78.333442] n_tty_receive_buf_common+0x7b0/0xc30 >>> [ 78.338128] n_tty_receive_buf+0x44/0x2c8 >>> [ 78.342122] tty_ioctl+0x348/0x11f8 >>> [ 78.345599] ksys_ioctl+0xd8/0xf8 >>> [ 78.348903] __arm64_sys_ioctl+0x2c/0xc8 >>> [ 78.352812] el0_svc_common.constprop.2+0x88/0x1b0 >>> [ 78.357583] do_el0_svc+0x44/0xd0 >>> [ 78.360887] el0_sync_handler+0x14c/0x1d0 >>> [ 78.364880] el0_sync+0x140/0x180 >>> [ 78.368185] Code: bad PC value >>> >>> SERIAL_PORT_DFNS is not defined on each arch, if it's not defined, >>> serial8250_set_defaults() won't be called in >>> serial8250_isa_init_ports(), >>> so the p->serial_in pointer won't be initialized, and it leads a >>> null-ptr-deref. >>> Fix this problem by calling serial8250_set_defaults() after init >>> uart port. >>> >>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> >>> --- >>> drivers/tty/serial/8250/8250_core.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >> Does this fix a specific commit, or has this issue always been present? >> What has caused it to happen now that no one else has seen this? > > I think it's always been present on the arch that not defined > SERIAL_PORT_DFNS. > > I got this on arm64 and here is the C reproducer: > > // autogenerated by syzkaller (https://github.com/google/syzkaller) > > #define _GNU_SOURCE > > #include <endian.h> > #include <stdint.h> > #include <stdio.h> > #include <stdlib.h> > #include <string.h> > #include <sys/syscall.h> > #include <sys/types.h> > #include <unistd.h> > > #ifndef __NR_ioctl > #define __NR_ioctl 29 > #endif > #ifndef __NR_mmap > #define __NR_mmap 222 > #endif > #ifndef __NR_openat > #define __NR_openat 56 > #endif > > uint64_t r[1] = {0xffffffffffffffff}; > > int main(void) > { > syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0); > intptr_t res = 0; > memcpy((void*)0x20000040, "/dev/ttyS3\000", 11); > res = syscall(__NR_openat, 0xffffffffffffff9cul, 0x20000040ul, > 0x401ul, 0ul); > if (res != -1) > r[0] = res; > syscall(__NR_ioctl, r[0], 0x5412ul, 0x20000080ul); > return 0; > } > It's can be reproduced with CONFIG_SERIAL_8250_RUNTIME_UARTS=8 and by opening ttyS4 on x86_64. Because the size of SERIAL_PORT_DFNS is 4 and the pointers of ttyS4 ~ ttyS7 won't be initialized. [ 49.427884] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 [ 49.432786] PGD 80000003d7573067 P4D 80000003d7573067 PUD 3d7526067 PMD 0 [ 49.436944] Oops: 0010 [#1] SMP KASAN PTI [ 49.439490] CPU: 1 PID: 2491 Comm: test Not tainted 4.19.90+ #1083 [ 49.443437] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 49.450233] RIP: 0010: (null) [ 49.452279] Code: Bad RIP value. [ 49.454066] RSP: 0018:ffff8883d73a7880 EFLAGS: 00010093 [ 49.457082] RAX: ffff8883d72d6000 RBX: ffffffff85e243a0 RCX: ffffffff820a062b [ 49.460916] RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffffffff85e243a0 [ 49.464490] RBP: 0000000000000002 R08: fffffbfff0bc4875 R09: fffffbfff0bc4874 [ 49.467993] R10: fffffbfff0bc4874 R11: ffffffff85e243a3 R12: ffffffff85e245f6 [ 49.471526] R13: ffffffff85e243f0 R14: 0000000000000000 R15: 0000000000000000 [ 49.475192] FS: 0000000002064880(0000) GS:ffff8883eb240000(0000) knlGS:0000000000000000 [ 49.479019] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.481852] CR2: ffffffffffffffd6 CR3: 00000003d77a2006 CR4: 0000000000020ee0 [ 49.485131] Call Trace: [ 49.486278] serial8250_start_tx+0x56c/0x9b0 [ 49.488167] __uart_start.isra.1+0x16a/0x1b0 [ 49.490082] uart_start+0x1a7/0x340 [ 49.491650] ? __uart_start.isra.1+0x1b0/0x1b0 [ 49.493670] ? __process_echoes+0x636/0x860 [ 49.495540] ? uart_start+0x340/0x340 [ 49.497442] n_tty_receive_buf_common+0x10ff/0x2460 [ 49.499897] ? n_tty_receive_buf2+0x40/0x40 [ 49.501915] tty_ioctl+0x6e1/0x1400 [ 49.503629] ? quarantine_put+0xb7/0x150 [ 49.505474] ? tty_vhangup+0x30/0x30 [ 49.507237] ? lockdep_hardirqs_on+0x290/0x560 [ 49.509419] ? __kasan_slab_free+0x1ce/0x230 [ 49.511490] ? kmem_cache_free+0xa6/0x2a0 [ 49.513454] ? putname+0xd4/0x110 [ 49.515059] ? do_sys_open+0x291/0x3f0 [ 49.516888] ? do_syscall_64+0x11c/0xe08 [ 49.518795] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 49.521359] ? __lock_acquire+0x5eb/0x2e50 [ 49.523278] ? restore_nameidata+0x108/0x180 [ 49.525242] ? tty_vhangup+0x30/0x30 [ 49.526895] do_vfs_ioctl+0x1a5/0x1100 [ 49.528608] ? may_open_dev+0xd0/0xd0 [ 49.530414] ? ioctl_preallocate+0x1d0/0x1d0 [ 49.532607] ? putname+0xd4/0x110 [ 49.534097] ? rcu_read_lock_sched_held+0x114/0x130 [ 49.536342] ? kmem_cache_free+0x263/0x2a0 [ 49.538450] ? putname+0xd4/0x110 [ 49.540036] ? do_sys_open+0x1ec/0x3f0 [ 49.541909] ksys_ioctl+0x7c/0xa0 [ 49.543458] __x64_sys_ioctl+0x74/0xb0 [ 49.545433] ? lockdep_hardirqs_on+0x37c/0x560 [ 49.547642] do_syscall_64+0x11c/0xe08 [ 49.549447] ? syscall_return_slowpath+0x3a0/0x3a0 [ 49.551741] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 49.553810] ? trace_hardirqs_off_caller+0x54/0x190 [ 49.556125] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 49.558453] entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Thanks, > > Yang > >> >> thanks, >> >> greg k-h >> . > > . ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] serial: 8250: fix null-ptr-deref in serial8250_start_tx() 2020-07-21 12:18 ` Yang Yingliang @ 2020-07-21 19:11 ` Greg KH 0 siblings, 0 replies; 6+ messages in thread From: Greg KH @ 2020-07-21 19:11 UTC (permalink / raw) To: Yang Yingliang Cc: linux-serial, linux-kernel, jslaby, Hanjun Guo, Libin (Huawei) On Tue, Jul 21, 2020 at 08:18:11PM +0800, Yang Yingliang wrote: > > On 2020/7/21 19:54, Yang Yingliang wrote: > > > > On 2020/7/21 18:48, Greg KH wrote: > > > On Tue, Jul 21, 2020 at 02:38:52PM +0000, Yang Yingliang wrote: > > > > I got null-ptr-deref in serial8250_start_tx(): > > > > > > > > [ 78.114630] Unable to handle kernel NULL pointer dereference > > > > at virtual address 0000000000000000 > > > > [ 78.123778] Mem abort info: > > > > [ 78.126560] ESR = 0x86000007 > > > > [ 78.129603] EC = 0x21: IABT (current EL), IL = 32 bits > > > > [ 78.134891] SET = 0, FnV = 0 > > > > [ 78.137933] EA = 0, S1PTW = 0 > > > > [ 78.141064] user pgtable: 64k pages, 48-bit VAs, > > > > pgdp=00000027d41a8600 > > > > [ 78.147562] [0000000000000000] pgd=00000027893f0003, > > > > p4d=00000027893f0003, pud=00000027893f0003, > > > > pmd=00000027c9a20003, pte=0000000000000000 > > > > [ 78.160029] Internal error: Oops: 86000007 [#1] SMP > > > > [ 78.164886] Modules linked in: sunrpc vfat fat aes_ce_blk > > > > crypto_simd cryptd aes_ce_cipher crct10dif_ce ghash_ce sha2_ce > > > > sha256_arm64 sha1_ce ses enclosure sg sbsa_gwdt ipmi_ssif > > > > spi_dw_mmio sch_fq_codel vhost_net tun vhost vhost_iotlb tap > > > > ip_tables ext4 mbcache jbd2 ahci hisi_sas_v3_hw libahci > > > > hisi_sas_main libsas hns3 scsi_transport_sas hclge libata > > > > megaraid_sas ipmi_si hnae3 ipmi_devintf ipmi_msghandler > > > > br_netfilter bridge stp llc nvme nvme_core xt_sctp sctp > > > > libcrc32c dm_mod nbd > > > > [ 78.207383] CPU: 11 PID: 23258 Comm: null-ptr Not tainted > > > > 5.8.0-rc6+ #48 > > > > [ 78.214056] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, > > > > BIOS 2280-V2 CS V3.B210.01 03/12/2020 > > > > [ 78.222888] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--) > > > > [ 78.228435] pc : 0x0 > > > > [ 78.230618] lr : serial8250_start_tx+0x160/0x260 > > > > [ 78.235215] sp : ffff800062eefb80 > > > > [ 78.238517] x29: ffff800062eefb80 x28: 0000000000000fff > > > > [ 78.243807] x27: ffff800062eefd80 x26: ffff202fd83b3000 > > > > [ 78.249098] x25: ffff800062eefd80 x24: ffff202fd83b3000 > > > > [ 78.254388] x23: ffff002fc5e50be8 x22: 0000000000000002 > > > > [ 78.259679] x21: 0000000000000001 x20: 0000000000000000 > > > > [ 78.264969] x19: ffffa688827eecc8 x18: 0000000000000000 > > > > [ 78.270259] x17: 0000000000000000 x16: 0000000000000000 > > > > [ 78.275550] x15: ffffa68881bc67a8 x14: 00000000000002e6 > > > > [ 78.280841] x13: ffffa68881bc67a8 x12: 000000000000c539 > > > > [ 78.286131] x11: d37a6f4de9bd37a7 x10: ffffa68881cccff0 > > > > [ 78.291421] x9 : ffffa68881bc6000 x8 : ffffa688819daa88 > > > > [ 78.296711] x7 : ffffa688822a0f20 x6 : ffffa688819e0000 > > > > [ 78.302002] x5 : ffff800062eef9d0 x4 : ffffa68881e707a8 > > > > [ 78.307292] x3 : 0000000000000000 x2 : 0000000000000002 > > > > [ 78.312582] x1 : 0000000000000001 x0 : ffffa688827eecc8 > > > > [ 78.317873] Call trace: > > > > [ 78.320312] 0x0 > > > > [ 78.322147] __uart_start.isra.9+0x64/0x78 > > > > [ 78.326229] uart_start+0xb8/0x1c8 > > > > [ 78.329620] uart_flush_chars+0x24/0x30 > > > > [ 78.333442] n_tty_receive_buf_common+0x7b0/0xc30 > > > > [ 78.338128] n_tty_receive_buf+0x44/0x2c8 > > > > [ 78.342122] tty_ioctl+0x348/0x11f8 > > > > [ 78.345599] ksys_ioctl+0xd8/0xf8 > > > > [ 78.348903] __arm64_sys_ioctl+0x2c/0xc8 > > > > [ 78.352812] el0_svc_common.constprop.2+0x88/0x1b0 > > > > [ 78.357583] do_el0_svc+0x44/0xd0 > > > > [ 78.360887] el0_sync_handler+0x14c/0x1d0 > > > > [ 78.364880] el0_sync+0x140/0x180 > > > > [ 78.368185] Code: bad PC value > > > > > > > > SERIAL_PORT_DFNS is not defined on each arch, if it's not defined, > > > > serial8250_set_defaults() won't be called in > > > > serial8250_isa_init_ports(), > > > > so the p->serial_in pointer won't be initialized, and it leads a > > > > null-ptr-deref. > > > > Fix this problem by calling serial8250_set_defaults() after init > > > > uart port. > > > > > > > > Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> > > > > --- > > > > drivers/tty/serial/8250/8250_core.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > Does this fix a specific commit, or has this issue always been present? > > > What has caused it to happen now that no one else has seen this? > > > > I think it's always been present on the arch that not defined > > SERIAL_PORT_DFNS. > > > > I got this on arm64 and here is the C reproducer: > > > > // autogenerated by syzkaller (https://github.com/google/syzkaller) > > > > #define _GNU_SOURCE > > > > #include <endian.h> > > #include <stdint.h> > > #include <stdio.h> > > #include <stdlib.h> > > #include <string.h> > > #include <sys/syscall.h> > > #include <sys/types.h> > > #include <unistd.h> > > > > #ifndef __NR_ioctl > > #define __NR_ioctl 29 > > #endif > > #ifndef __NR_mmap > > #define __NR_mmap 222 > > #endif > > #ifndef __NR_openat > > #define __NR_openat 56 > > #endif > > > > uint64_t r[1] = {0xffffffffffffffff}; > > > > int main(void) > > { > > syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0); > > intptr_t res = 0; > > memcpy((void*)0x20000040, "/dev/ttyS3\000", 11); > > res = syscall(__NR_openat, 0xffffffffffffff9cul, 0x20000040ul, > > 0x401ul, 0ul); > > if (res != -1) > > r[0] = res; > > syscall(__NR_ioctl, r[0], 0x5412ul, 0x20000080ul); > > return 0; > > } > > > It's can be reproduced with CONFIG_SERIAL_8250_RUNTIME_UARTS=8 and > > by opening ttyS4 on x86_64. Because the size of SERIAL_PORT_DFNS is 4 and > > the pointers of ttyS4 ~ ttyS7 won't be initialized. Ah, good catch, yeah, that's not nice. I'll go queue this up now, thanks for the fix! greg k-h ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] serial: 8250: fix null-ptr-deref in serial8250_start_tx() 2020-07-21 14:38 [PATCH] serial: 8250: fix null-ptr-deref in serial8250_start_tx() Yang Yingliang 2020-07-21 10:48 ` Greg KH @ 2020-07-22 1:56 ` liwei (GF) 1 sibling, 0 replies; 6+ messages in thread From: liwei (GF) @ 2020-07-22 1:56 UTC (permalink / raw) To: Yang Yingliang, gregkh; +Cc: jslaby, LKML, linux-serial Hi Yingliang, On 2020/7/21 22:38, Yang Yingliang wrote: (SNIP) > > SERIAL_PORT_DFNS is not defined on each arch, if it's not defined, > serial8250_set_defaults() won't be called in serial8250_isa_init_ports(), > so the p->serial_in pointer won't be initialized, and it leads a null-ptr-deref. > Fix this problem by calling serial8250_set_defaults() after init uart port. > > Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> > --- > drivers/tty/serial/8250/8250_core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c > index fc118f649887..cae61d1ebec5 100644 > --- a/drivers/tty/serial/8250/8250_core.c > +++ b/drivers/tty/serial/8250/8250_core.c > @@ -524,6 +524,7 @@ static void __init serial8250_isa_init_ports(void) > */ > up->mcr_mask = ~ALPHA_KLUDGE_MCR; > up->mcr_force = ALPHA_KLUDGE_MCR; > + serial8250_set_defaults(up); That is really a good catch, but this modification looks not good to me. First, serial8250_set_defaults()'s parameter 'up' updated in the loop below is used to lead to different branch in this function. So that the logic is broken. Second, up->port.iobase and up->port.iotype are both initialized to 0, so the 'serial_in' and 'serial_out' will be assigned to the ops for IO space with port 0 here, i don't think that is correct. > } > > /* chain base port ops to support Remote Supervisor Adapter */ > @@ -547,7 +548,6 @@ static void __init serial8250_isa_init_ports(void) > port->membase = old_serial_port[i].iomem_base; > port->iotype = old_serial_port[i].io_type; > port->regshift = old_serial_port[i].iomem_reg_shift; > - serial8250_set_defaults(up); > > port->irqflags |= irqflag; > if (serial8250_isa_config != NULL) > Thanks, Wei ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-07-22 2:03 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-07-21 14:38 [PATCH] serial: 8250: fix null-ptr-deref in serial8250_start_tx() Yang Yingliang 2020-07-21 10:48 ` Greg KH 2020-07-21 11:54 ` Yang Yingliang 2020-07-21 12:18 ` Yang Yingliang 2020-07-21 19:11 ` Greg KH 2020-07-22 1:56 ` liwei (GF)
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