From: Yongqiang Liu <liuyongqiang13@huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ID4844 -------------------------------- Unaligned access is harmful for non-x86 archs such as arm64. When we use pwrite or pread to access the I/O port resources with unaligned offset, system will crash as follows: Unable to handle kernel paging request at virtual address fffffbfffe8010c1 Internal error: Oops: 0000000096000061 [#1] SMP Modules linked in: CPU: 1 PID: 44230 Comm: syz.1.10955 Not tainted 6.6.0+ #1 Hardware name: linux,dummy-virt (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __raw_writew arch/arm64/include/asm/io.h:33 [inline] pc : _outw include/asm-generic/io.h:594 [inline] pc : logic_outw+0x54/0x218 lib/logic_pio.c:305 lr : _outw include/asm-generic/io.h:593 [inline] lr : logic_outw+0x40/0x218 lib/logic_pio.c:305 sp : ffff800083097a30 x29: ffff800083097a30 x28: ffffba71ba86e130 x27: 1ffff00010612f93 x26: ffff3bae63b3a420 x25: ffffba71bbf585d0 x24: 0000000000005ac1 x23: 00000000000010c1 x22: ffff3baf0deb6488 x21: 0000000000000002 x20: 00000000000010c1 x19: 0000000000ffbffe x18: 0000000000000000 x17: 0000000000000000 x16: ffffba71b9f44b48 x15: 00000000200002c0 x14: 0000000000000000 x13: 0000000000000000 x12: ffff6775ca80451f x11: 1fffe775ca80451e x10: ffff6775ca80451e x9 : ffffba71bb78cf2c x8 : 0000988a357fbae2 x7 : ffff3bae540228f7 x6 : 0000000000000001 x5 : 1fffe775e2b43c78 x4 : dfff800000000000 x3 : ffffba71b9a00000 x2 : ffff80008d22a000 x1 : ffffc58ec6600000 x0 : fffffbfffe8010c1 Call trace: _outw include/asm-generic/io.h:594 [inline] logic_outw+0x54/0x218 lib/logic_pio.c:305 pci_resource_io drivers/pci/pci-sysfs.c:1157 [inline] pci_write_resource_io drivers/pci/pci-sysfs.c:1191 [inline] pci_write_resource_io+0x208/0x260 drivers/pci/pci-sysfs.c:1181 sysfs_kf_bin_write+0x188/0x210 fs/sysfs/file.c:158 kernfs_fop_write_iter+0x2e8/0x4b0 fs/kernfs/file.c:338 call_write_iter include/linux/fs.h:2085 [inline] new_sync_write fs/read_write.c:493 [inline] vfs_write+0x7bc/0xac8 fs/read_write.c:586 ksys_write+0x12c/0x270 fs/read_write.c:639 __do_sys_write fs/read_write.c:651 [inline] __se_sys_write fs/read_write.c:648 [inline] __arm64_sys_write+0x78/0xb8 fs/read_write.c:648 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x8c/0x2e0 arch/arm64/kernel/syscall.c:51 el0_svc_common.constprop.0+0x200/0x2a8 arch/arm64/kernel/syscall.c:134 do_el0_svc+0x4c/0x70 arch/arm64/kernel/syscall.c:176 el0_svc+0x44/0x1d8 arch/arm64/kernel/entry-common.c:806 el0t_64_sync_handler+0x100/0x130 arch/arm64/kernel/entry-common.c:844 el0t_64_sync+0x3c8/0x3d0 arch/arm64/kernel/entry.S:757 Powerpc seems affected as well, so prohibit the unaligned access on non-x86 archs. Fixes: 8633328be242 ("PCI: Allow read/write access to sysfs I/O port resources") Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> Signed-off-by: Ziming Du <duziming2@huawei.com> --- drivers/pci/pci-sysfs.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 48c56cb086524..e8c3a1b7d4a93 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1204,6 +1204,13 @@ static int pci_mmap_resource_wc(struct file *filp, struct kobject *kobj, return pci_mmap_resource(kobj, attr, vma, 1); } +#if !defined(CONFIG_X86) +static bool is_unaligned(unsigned long port, size_t size) +{ + return port & (size - 1); +} +#endif + static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count, bool write) @@ -1220,6 +1227,11 @@ static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj, if (port + count - 1 > pci_resource_end(pdev, bar)) return -EINVAL; +#if !defined(CONFIG_X86) + if (is_unaligned(port, count)) + return -EFAULT; +#endif + switch (count) { case 1: if (write) -- 2.43.0