March 2020 - Linux-stable-mirror

[tip: smp/core] cpu/hotplug: Ignore pm_wakeup_pending() for disable_nonboot_cpus()

by tip-bot2 for Thomas Gleixner

The following commit has been merged into the smp/core branch of tip: Commit-ID: e98eac6ff1b45e4e73f2e6031b37c256ccb5d36b Gitweb: https://git.kernel.org/tip/e98eac6ff1b45e4e73f2e6031b37c256ccb5d36b Author: Thomas Gleixner <tglx(a)linutronix.de> AuthorDate: Fri, 27 Mar 2020 12:06:44 +01:00 Committer: Thomas Gleixner <tglx(a)linutronix.de> CommitterDate: Sat, 28 Mar 2020 11:42:55 +01:00 cpu/hotplug: Ignore pm_wakeup_pending() for disable_nonboot_cpus() A recent change to freeze_secondary_cpus() which added an early abort if a wakeup is pending missed the fact that the function is also invoked for shutdown, reboot and kexec via disable_nonboot_cpus(). In case of disable_nonboot_cpus() the wakeup event needs to be ignored as the purpose is to terminate the currently running kernel. Add a 'suspend' argument which is only set when the freeze is in context of a suspend operation. If not set then an eventually pending wakeup event is ignored. Fixes: a66d955e910a ("cpu/hotplug: Abort disabling secondary CPUs if wakeup is pending") Reported-by: Boqun Feng <boqun.feng(a)gmail.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Pavankumar Kondeti <pkondeti(a)codeaurora.org> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/874kuaxdiz.fsf@nanos.tec.linutronix.de --- include/linux/cpu.h | 12 +++++++++--- kernel/cpu.c | 4 ++-- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 9ead281..beaed2d 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -144,12 +144,18 @@ static inline void get_online_cpus(void) { cpus_read_lock(); } static inline void put_online_cpus(void) { cpus_read_unlock(); } #ifdef CONFIG_PM_SLEEP_SMP -extern int freeze_secondary_cpus(int primary); +int __freeze_secondary_cpus(int primary, bool suspend); +static inline int freeze_secondary_cpus(int primary) +{ + return __freeze_secondary_cpus(primary, true); +} + static inline int disable_nonboot_cpus(void) { - return freeze_secondary_cpus(0); + return __freeze_secondary_cpus(0, false); } -extern void enable_nonboot_cpus(void); + +void enable_nonboot_cpus(void); static inline int suspend_disable_secondary_cpus(void) { diff --git a/kernel/cpu.c b/kernel/cpu.c index 3084849..12ae636 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1327,7 +1327,7 @@ void bringup_nonboot_cpus(unsigned int setup_max_cpus) #ifdef CONFIG_PM_SLEEP_SMP static cpumask_var_t frozen_cpus; -int freeze_secondary_cpus(int primary) +int __freeze_secondary_cpus(int primary, bool suspend) { int cpu, error = 0; @@ -1352,7 +1352,7 @@ int freeze_secondary_cpus(int primary) if (cpu == primary) continue; - if (pm_wakeup_pending()) { + if (suspend && pm_wakeup_pending()) { pr_info("Wakeup pending. Abort CPU freeze\n"); error = -EBUSY; break;

4 years, 9 months

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[PATCHES] Networking

by David Miller

Please queue up the following networking bug fixes for v5.4 and v5.5 -stable, respectively. Thank you.

4 years, 9 months

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patch "vt: vt_ioctl: fix use-after-free in vt_in_use()" added to tty-next

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled vt: vt_ioctl: fix use-after-free in vt_in_use() to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. >From 7cf64b18b0b96e751178b8d0505d8466ff5a448f Mon Sep 17 00:00:00 2001 From: Eric Biggers <ebiggers(a)google.com> Date: Sat, 21 Mar 2020 20:43:05 -0700 Subject: vt: vt_ioctl: fix use-after-free in vt_in_use() vt_in_use() dereferences console_driver->ttys[i] without proper locking. This is broken because the tty can be closed and freed concurrently. We could fix this by using 'READ_ONCE(console_driver->ttys[i]) != NULL' and skipping the check of tty_struct::count. But, looking at console_driver->ttys[i] isn't really appropriate anyway because even if it is NULL the tty can still be in the process of being closed. Instead, fix it by making vt_in_use() require console_lock() and check whether the vt is allocated and has port refcount > 1. This works since following the patch "vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console" the port refcount is incremented while the vt is open. Reproducer (very unreliable, but it worked for me after a few minutes): #include <fcntl.h> #include <linux/vt.h> int main() { int fd, nproc; struct vt_stat state; char ttyname[16]; fd = open("/dev/tty10", O_RDONLY); for (nproc = 1; nproc < 8; nproc *= 2) fork(); for (;;) { sprintf(ttyname, "/dev/tty%d", rand() % 8); close(open(ttyname, O_RDONLY)); ioctl(fd, VT_GETSTATE, &state); } } KASAN report: BUG: KASAN: use-after-free in vt_in_use drivers/tty/vt/vt_ioctl.c:48 [inline] BUG: KASAN: use-after-free in vt_ioctl+0x1ad3/0x1d70 drivers/tty/vt/vt_ioctl.c:657 Read of size 4 at addr ffff888065722468 by task syz-vt2/132 CPU: 0 PID: 132 Comm: syz-vt2 Not tainted 5.6.0-rc5-00130-g089b6d3654916 #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014 Call Trace: [...] vt_in_use drivers/tty/vt/vt_ioctl.c:48 [inline] vt_ioctl+0x1ad3/0x1d70 drivers/tty/vt/vt_ioctl.c:657 tty_ioctl+0x9db/0x11b0 drivers/tty/tty_io.c:2660 [...] Allocated by task 136: [...] kzalloc include/linux/slab.h:669 [inline] alloc_tty_struct+0x96/0x8a0 drivers/tty/tty_io.c:2982 tty_init_dev+0x23/0x350 drivers/tty/tty_io.c:1334 tty_open_by_driver drivers/tty/tty_io.c:1987 [inline] tty_open+0x3ca/0xb30 drivers/tty/tty_io.c:2035 [...] Freed by task 41: [...] kfree+0xbf/0x200 mm/slab.c:3757 free_tty_struct+0x8d/0xb0 drivers/tty/tty_io.c:177 release_one_tty+0x22d/0x2f0 drivers/tty/tty_io.c:1468 process_one_work+0x7f1/0x14b0 kernel/workqueue.c:2264 worker_thread+0x8b/0xc80 kernel/workqueue.c:2410 [...] Fixes: 4001d7b7fc27 ("vt: push down the tty lock so we can see what is left to tackle") Cc: <stable(a)vger.kernel.org> # v3.4+ Acked-by: Jiri Slaby <jslaby(a)suse.cz> Signed-off-by: Eric Biggers <ebiggers(a)google.com> Link: https://lore.kernel.org/r/20200322034305.210082-3-ebiggers@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/tty/vt/vt_ioctl.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c index f62f498f63c0..daf61c28ba76 100644 --- a/drivers/tty/vt/vt_ioctl.c +++ b/drivers/tty/vt/vt_ioctl.c @@ -43,9 +43,15 @@ bool vt_dont_switch; static inline bool vt_in_use(unsigned int i) { - extern struct tty_driver *console_driver; + const struct vc_data *vc = vc_cons[i].d; - return console_driver->ttys[i] && console_driver->ttys[i]->count; + /* + * console_lock must be held to prevent the vc from being deallocated + * while we're checking whether it's in-use. + */ + WARN_CONSOLE_UNLOCKED(); + + return vc && kref_read(&vc->port.kref) > 1; } static inline bool vt_busy(int i) @@ -643,15 +649,16 @@ int vt_ioctl(struct tty_struct *tty, struct vt_stat __user *vtstat = up; unsigned short state, mask; - /* Review: FIXME: Console lock ? */ if (put_user(fg_console + 1, &vtstat->v_active)) ret = -EFAULT; else { state = 1; /* /dev/tty0 is always open */ + console_lock(); /* required by vt_in_use() */ for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask; ++i, mask <<= 1) if (vt_in_use(i)) state |= mask; + console_unlock(); ret = put_user(state, &vtstat->v_state); } break; @@ -661,10 +668,11 @@ int vt_ioctl(struct tty_struct *tty, * Returns the first available (non-opened) console. */ case VT_OPENQRY: - /* FIXME: locking ? - but then this is a stupid API */ + console_lock(); /* required by vt_in_use() */ for (i = 0; i < MAX_NR_CONSOLES; ++i) if (!vt_in_use(i)) break; + console_unlock(); uival = i < MAX_NR_CONSOLES ? (i+1) : -1; goto setint; -- 2.26.0

4 years, 9 months

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patch "vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console" added to tty-next

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. >From ca4463bf8438b403596edd0ec961ca0d4fbe0220 Mon Sep 17 00:00:00 2001 From: Eric Biggers <ebiggers(a)google.com> Date: Sat, 21 Mar 2020 20:43:04 -0700 Subject: vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console The VT_DISALLOCATE ioctl can free a virtual console while tty_release() is still running, causing a use-after-free in con_shutdown(). This occurs because VT_DISALLOCATE considers a virtual console's 'struct vc_data' to be unused as soon as the corresponding tty's refcount hits 0. But actually it may be still being closed. Fix this by making vc_data be reference-counted via the embedded 'struct tty_port'. A newly allocated virtual console has refcount 1. Opening it for the first time increments the refcount to 2. Closing it for the last time decrements the refcount (in tty_operations::cleanup() so that it happens late enough), as does VT_DISALLOCATE. Reproducer: #include <fcntl.h> #include <linux/vt.h> #include <sys/ioctl.h> #include <unistd.h> int main() { if (fork()) { for (;;) close(open("/dev/tty5", O_RDWR)); } else { int fd = open("/dev/tty10", O_RDWR); for (;;) ioctl(fd, VT_DISALLOCATE, 5); } } KASAN report: BUG: KASAN: use-after-free in con_shutdown+0x76/0x80 drivers/tty/vt/vt.c:3278 Write of size 8 at addr ffff88806a4ec108 by task syz_vt/129 CPU: 0 PID: 129 Comm: syz_vt Not tainted 5.6.0-rc2 #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014 Call Trace: [...] con_shutdown+0x76/0x80 drivers/tty/vt/vt.c:3278 release_tty+0xa8/0x410 drivers/tty/tty_io.c:1514 tty_release_struct+0x34/0x50 drivers/tty/tty_io.c:1629 tty_release+0x984/0xed0 drivers/tty/tty_io.c:1789 [...] Allocated by task 129: [...] kzalloc include/linux/slab.h:669 [inline] vc_allocate drivers/tty/vt/vt.c:1085 [inline] vc_allocate+0x1ac/0x680 drivers/tty/vt/vt.c:1066 con_install+0x4d/0x3f0 drivers/tty/vt/vt.c:3229 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline] tty_init_dev+0x94/0x350 drivers/tty/tty_io.c:1341 tty_open_by_driver drivers/tty/tty_io.c:1987 [inline] tty_open+0x3ca/0xb30 drivers/tty/tty_io.c:2035 [...] Freed by task 130: [...] kfree+0xbf/0x1e0 mm/slab.c:3757 vt_disallocate drivers/tty/vt/vt_ioctl.c:300 [inline] vt_ioctl+0x16dc/0x1e30 drivers/tty/vt/vt_ioctl.c:818 tty_ioctl+0x9db/0x11b0 drivers/tty/tty_io.c:2660 [...] Fixes: 4001d7b7fc27 ("vt: push down the tty lock so we can see what is left to tackle") Cc: <stable(a)vger.kernel.org> # v3.4+ Reported-by: syzbot+522643ab5729b0421998(a)syzkaller.appspotmail.com Acked-by: Jiri Slaby <jslaby(a)suse.cz> Signed-off-by: Eric Biggers <ebiggers(a)google.com> Link: https://lore.kernel.org/r/20200322034305.210082-2-ebiggers@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/tty/vt/vt.c | 23 ++++++++++++++++++++++- drivers/tty/vt/vt_ioctl.c | 12 ++++-------- 2 files changed, 26 insertions(+), 9 deletions(-) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index bbc26d73209a..309a39197be0 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -1075,6 +1075,17 @@ static void visual_deinit(struct vc_data *vc) module_put(vc->vc_sw->owner); } +static void vc_port_destruct(struct tty_port *port) +{ + struct vc_data *vc = container_of(port, struct vc_data, port); + + kfree(vc); +} + +static const struct tty_port_operations vc_port_ops = { + .destruct = vc_port_destruct, +}; + int vc_allocate(unsigned int currcons) /* return 0 on success */ { struct vt_notifier_param param; @@ -1100,6 +1111,7 @@ int vc_allocate(unsigned int currcons) /* return 0 on success */ vc_cons[currcons].d = vc; tty_port_init(&vc->port); + vc->port.ops = &vc_port_ops; INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK); visual_init(vc, currcons, 1); @@ -3250,6 +3262,7 @@ static int con_install(struct tty_driver *driver, struct tty_struct *tty) tty->driver_data = vc; vc->port.tty = tty; + tty_port_get(&vc->port); if (!tty->winsize.ws_row && !tty->winsize.ws_col) { tty->winsize.ws_row = vc_cons[currcons].d->vc_rows; @@ -3285,6 +3298,13 @@ static void con_shutdown(struct tty_struct *tty) console_unlock(); } +static void con_cleanup(struct tty_struct *tty) +{ + struct vc_data *vc = tty->driver_data; + + tty_port_put(&vc->port); +} + static int default_color = 7; /* white */ static int default_italic_color = 2; // green (ASCII) static int default_underline_color = 3; // cyan (ASCII) @@ -3410,7 +3430,8 @@ static const struct tty_operations con_ops = { .throttle = con_throttle, .unthrottle = con_unthrottle, .resize = vt_resize, - .shutdown = con_shutdown + .shutdown = con_shutdown, + .cleanup = con_cleanup, }; static struct cdev vc0_cdev; diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c index 7297997fcf04..f62f498f63c0 100644 --- a/drivers/tty/vt/vt_ioctl.c +++ b/drivers/tty/vt/vt_ioctl.c @@ -310,10 +310,8 @@ static int vt_disallocate(unsigned int vc_num) vc = vc_deallocate(vc_num); console_unlock(); - if (vc && vc_num >= MIN_NR_CONSOLES) { - tty_port_destroy(&vc->port); - kfree(vc); - } + if (vc && vc_num >= MIN_NR_CONSOLES) + tty_port_put(&vc->port); return ret; } @@ -333,10 +331,8 @@ static void vt_disallocate_all(void) console_unlock(); for (i = 1; i < MAX_NR_CONSOLES; i++) { - if (vc[i] && i >= MIN_NR_CONSOLES) { - tty_port_destroy(&vc[i]->port); - kfree(vc[i]); - } + if (vc[i] && i >= MIN_NR_CONSOLES) + tty_port_put(&vc[i]->port); } } -- 2.26.0

4 years, 9 months

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patch "USB: cdc-acm: restore capability check order" added to usb-next

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled USB: cdc-acm: restore capability check order to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. >From 62d65bdd9d05158aa2547f8ef72375535f3bc6e3 Mon Sep 17 00:00:00 2001 From: Matthias Reichl <hias(a)horus.com> Date: Fri, 27 Mar 2020 16:03:50 +0100 Subject: USB: cdc-acm: restore capability check order commit b401f8c4f492c ("USB: cdc-acm: fix rounding error in TIOCSSERIAL") introduced a regression by changing the order of capability and close settings change checks. When running with CAP_SYS_ADMIN setting the close settings to the values already set resulted in -EOPNOTSUPP. Fix this by changing the check order back to how it was before. Fixes: b401f8c4f492c ("USB: cdc-acm: fix rounding error in TIOCSSERIAL") Cc: Anthony Mallet <anthony.mallet(a)laas.fr> Cc: stable <stable(a)vger.kernel.org> Cc: Oliver Neukum <oneukum(a)suse.com> Signed-off-by: Matthias Reichl <hias(a)horus.com> Link: https://lore.kernel.org/r/20200327150350.3657-1-hias@horus.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/usb/class/cdc-acm.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 47f09a6ce7bd..84d6f7df09a4 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -923,16 +923,16 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) mutex_lock(&acm->port.mutex); - if ((ss->close_delay != old_close_delay) || - (ss->closing_wait != old_closing_wait)) { - if (!capable(CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN)) { + if ((ss->close_delay != old_close_delay) || + (ss->closing_wait != old_closing_wait)) retval = -EPERM; - else { - acm->port.close_delay = close_delay; - acm->port.closing_wait = closing_wait; - } - } else - retval = -EOPNOTSUPP; + else + retval = -EOPNOTSUPP; + } else { + acm->port.close_delay = close_delay; + acm->port.closing_wait = closing_wait; + } mutex_unlock(&acm->port.mutex); return retval; -- 2.26.0

4 years, 9 months

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[PATCH] MIPS/tlbex: Fix LDDIR usage in setup_pw() for Loongson-3

by Huacai Chen

LDDIR/LDPTE is Loongson-3's acceleration for Page Table Walking. If BD (Base Directory, the 4th page directory) is not enabled, then GDOffset is biased by BadVAddr[63:62]. So, if GDOffset (aka. BadVAddr[47:36] for Loongson-3) is big enough, "0b11(BadVAddr[63:62])|BadVAddr[47:36]|...." can far beyond pg_swapper_dir. This means the pg_swapper_dir may NOT be accessed by LDDIR correctly, so fix it by set PWDirExt in CP0_PWCtl. Cc: <stable(a)vger.kernel.org> Signed-off-by: Pei Huang <huangpei(a)loongson.cn> Signed-off-by: Huacai Chen <chenhc(a)lemote.com> --- arch/mips/mm/tlbex.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index 344e6e9..da407cd 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -1480,6 +1480,7 @@ static void build_r4000_tlb_refill_handler(void) static void setup_pw(void) { + unsigned int pwctl; unsigned long pgd_i, pgd_w; #ifndef __PAGETABLE_PMD_FOLDED unsigned long pmd_i, pmd_w; @@ -1506,6 +1507,7 @@ static void setup_pw(void) pte_i = ilog2(_PAGE_GLOBAL); pte_w = 0; + pwctl = 1 << 30; /* Set PWDirExt */ #ifndef __PAGETABLE_PMD_FOLDED write_c0_pwfield(pgd_i << 24 | pmd_i << 12 | pt_i << 6 | pte_i); @@ -1516,8 +1518,9 @@ static void setup_pw(void) #endif #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT - write_c0_pwctl(1 << 6 | psn); + pwctl |= (1 << 6 | psn); #endif + write_c0_pwctl(pwctl); write_c0_kpgd((long)swapper_pg_dir); kscratch_used_mask |= (1 << 7); /* KScratch6 is used for KPGD */ } -- 2.7.0

4 years, 9 months

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[PATCH v3] mm/hugetlb: fix a addressing exception caused by huge_pte_offset

by Longpeng(Mike)

From: Longpeng <longpeng2(a)huawei.com> Our machine encountered a panic(addressing exception) after run for a long time and the calltrace is: RIP: 0010:[<ffffffff9dff0587>] [<ffffffff9dff0587>] hugetlb_fault+0x307/0xbe0 RSP: 0018:ffff9567fc27f808 EFLAGS: 00010286 RAX: e800c03ff1258d48 RBX: ffffd3bb003b69c0 RCX: e800c03ff1258d48 RDX: 17ff3fc00eda72b7 RSI: 00003ffffffff000 RDI: e800c03ff1258d48 RBP: ffff9567fc27f8c8 R08: e800c03ff1258d48 R09: 0000000000000080 R10: ffffaba0704c22a8 R11: 0000000000000001 R12: ffff95c87b4b60d8 R13: 00005fff00000000 R14: 0000000000000000 R15: ffff9567face8074 FS: 00007fe2d9ffb700(0000) GS:ffff956900e40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffd3bb003b69c0 CR3: 000000be67374000 CR4: 00000000003627e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: [<ffffffff9df9b71b>] ? unlock_page+0x2b/0x30 [<ffffffff9dff04a2>] ? hugetlb_fault+0x222/0xbe0 [<ffffffff9dff1405>] follow_hugetlb_page+0x175/0x540 [<ffffffff9e15b825>] ? cpumask_next_and+0x35/0x50 [<ffffffff9dfc7230>] __get_user_pages+0x2a0/0x7e0 [<ffffffff9dfc648d>] __get_user_pages_unlocked+0x15d/0x210 [<ffffffffc068cfc5>] __gfn_to_pfn_memslot+0x3c5/0x460 [kvm] [<ffffffffc06b28be>] try_async_pf+0x6e/0x2a0 [kvm] [<ffffffffc06b4b41>] tdp_page_fault+0x151/0x2d0 [kvm] ... [<ffffffffc06a6f90>] kvm_arch_vcpu_ioctl_run+0x330/0x490 [kvm] [<ffffffffc068d919>] kvm_vcpu_ioctl+0x309/0x6d0 [kvm] [<ffffffff9deaa8c2>] ? dequeue_signal+0x32/0x180 [<ffffffff9deae34d>] ? do_sigtimedwait+0xcd/0x230 [<ffffffff9e03aed0>] do_vfs_ioctl+0x3f0/0x540 [<ffffffff9e03b0c1>] SyS_ioctl+0xa1/0xc0 [<ffffffff9e53879b>] system_call_fastpath+0x22/0x27 For 1G hugepages, huge_pte_offset() wants to return NULL or pudp, but it may return a wrong 'pmdp' if there is a race. Please look at the following code snippet: ... pud = pud_offset(p4d, addr); if (sz != PUD_SIZE && pud_none(*pud)) return NULL; /* hugepage or swap? */ if (pud_huge(*pud) || !pud_present(*pud)) return (pte_t *)pud; pmd = pmd_offset(pud, addr); if (sz != PMD_SIZE && pmd_none(*pmd)) return NULL; /* hugepage or swap? */ if (pmd_huge(*pmd) || !pmd_present(*pmd)) return (pte_t *)pmd; ... The following sequence would trigger this bug: 1. CPU0: sz = PUD_SIZE and *pud = 0 , continue 1. CPU0: "pud_huge(*pud)" is false 2. CPU1: calling hugetlb_no_page and set *pud to xxxx8e7(PRESENT) 3. CPU0: "!pud_present(*pud)" is false, continue 4. CPU0: pmd = pmd_offset(pud, addr) and maybe return a wrong pmdp However, we want CPU0 to return NULL or pudp in this case. Also, according to the section 'COMPILER BARRIER' of memory-barriers.txt: ''' (*) The compiler is within its rights to reorder loads and stores to the same variable, and in some cases, the CPU is within its rights to reorder loads to the same variable. This means that the following code: a[0] = x; a[1] = x; Might result in an older value of x stored in a[1] than in a[0]. ''' there're several other data races in huge_pte_offset, for example: ''' p4d = p4d_offset(pgd, addr) if (!p4d_present(*p4d)) return NULL; pud = pud_offset(p4d, addr) <-- will be unwinded as: pud = (pud_t *)p4d_page_vaddr(*p4d) + pud_index(address); ''' which is free for the compiler/CPU to execute as: ''' p4d = p4d_offset(pgd, addr) p4d_for_vaddr = *p4d; if (!p4d_present(*p4d)) return NULL; pud = (pud_t *)p4d_page_vaddr(p4d_for_vaddr) + pud_index(address); ''' so in the case where *p4g goes from '!present' to 'present': p4d_present(*p4d) and p4d_for_vaddr == none, meaning the p4d_page_vaddr() will crash. For these reasons, we must make sure there is exactly one dereference of p4g, pud and pmd. Cc: Mike Kravetz <mike.kravetz(a)oracle.com> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Jason Gunthorpe <jgg(a)ziepe.ca> Cc: Matthew Wilcox <willy(a)infradead.org> Cc: Sean Christopherson <sean.j.christopherson(a)intel.com> Cc: stable(a)vger.kernel.org Suggested-by: Jason Gunthorpe <jgg(a)ziepe.ca> Signed-off-by: Longpeng <longpeng2(a)huawei.com> --- v2 -> v3: make sure p4g/pud/pmd be dereferenced once. [Jason] --- mm/hugetlb.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index dd8737a..d4fab68 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4909,29 +4909,33 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long sz) { pgd_t *pgd; - p4d_t *p4d; - pud_t *pud; - pmd_t *pmd; + p4d_t *p4g, p4d_entry; + pud_t *pud, pud_entry; + pmd_t *pmd, pmd_entry; pgd = pgd_offset(mm, addr); if (!pgd_present(*pgd)) return NULL; - p4d = p4d_offset(pgd, addr); - if (!p4d_present(*p4d)) + + p4g = p4d_offset(pgd, addr); + p4d_entry = READ_ONCE(*p4g); + if (!p4d_present(p4d_entry)) return NULL; - pud = pud_offset(p4d, addr); - if (sz != PUD_SIZE && pud_none(*pud)) + pud = pud_offset(&p4d_entry, addr); + pud_entry = READ_ONCE(*pud); + if (sz != PUD_SIZE && pud_none(pud_entry)) return NULL; /* hugepage or swap? */ - if (pud_huge(*pud) || !pud_present(*pud)) + if (pud_huge(pud_entry) || !pud_present(pud_entry)) return (pte_t *)pud; - pmd = pmd_offset(pud, addr); - if (sz != PMD_SIZE && pmd_none(*pmd)) + pmd = pmd_offset(&pud_entry, addr); + pmd_entry = READ_ONCE(*pmd); + if (sz != PMD_SIZE && pmd_none(pmd_entry)) return NULL; /* hugepage or swap? */ - if (pmd_huge(*pmd) || !pmd_present(*pmd)) + if (pmd_huge(pmd_entry) || !pmd_present(pmd_entry)) return (pte_t *)pmd; return NULL; -- 1.8.3.1

4 years, 9 months

4
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[PATCH v2 2/3] platform/x86: intel-hid: fix: Update Tiger Lake ACPI device ID

by Gayatri Kammela

Tiger Lake's new unique ACPI device IDs for intel-hid driver is not valid because of missing 'C' in the ID. Fix the ID by updating it. After the update, the new ID should now look like INT1051 --> INTC1051 Fixes: bdd11b654035 ("platform/x86: intel-hid: Add Tiger Lake ACPI device ID") Cc: 5.6+ <stable(a)vger.kernel.org> # 5.6+ Cc: Andy Shevchenko <andriy.shevchenko(a)linux.intel.com> Cc: Srinivas Pandruvada <srinivas.pandruvada(a)intel.com> Cc: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com> Suggested-by: Srinivas Pandruvada <srinivas.pandruvada(a)intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela(a)intel.com> --- drivers/platform/x86/intel-hid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/platform/x86/intel-hid.c b/drivers/platform/x86/intel-hid.c index 43d590250228..c0a4696803eb 100644 --- a/drivers/platform/x86/intel-hid.c +++ b/drivers/platform/x86/intel-hid.c @@ -19,7 +19,7 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Alex Hung"); static const struct acpi_device_id intel_hid_ids[] = { - {"INT1051", 0}, + {"INTC1051", 0}, {"INT33D5", 0}, {"", 0}, }; -- 2.17.1

4 years, 9 months

1
0
0 0

[PATCH] tools: gpio: Fix out-of-tree build regression

by Anssi Hannula

Commit 0161a94e2d1c7 ("tools: gpio: Correctly add make dependencies for gpio_utils") added a make rule for gpio-utils-in.o but used $(output) instead of the correct $(OUTPUT) for the output directory, breaking out-of-tree build (O=xx) with the following error: No rule to make target 'out/tools/gpio/gpio-utils-in.o', needed by 'out/tools/gpio/lsgpio-in.o'. Stop. Fix that. Fixes: 0161a94e2d1c ("tools: gpio: Correctly add make dependencies for gpio_utils") Cc: <stable(a)vger.kernel.org> Cc: Laura Abbott <labbott(a)redhat.com> Signed-off-by: Anssi Hannula <anssi.hannula(a)bitwise.fi> --- The 0161a94e2d1c was also applied to stable releases, which is where I got hit by the issue. tools/gpio/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/gpio/Makefile b/tools/gpio/Makefile index 842287e42c83..440434027557 100644 --- a/tools/gpio/Makefile +++ b/tools/gpio/Makefile @@ -35,7 +35,7 @@ $(OUTPUT)include/linux/gpio.h: ../../include/uapi/linux/gpio.h prepare: $(OUTPUT)include/linux/gpio.h -GPIO_UTILS_IN := $(output)gpio-utils-in.o +GPIO_UTILS_IN := $(OUTPUT)gpio-utils-in.o $(GPIO_UTILS_IN): prepare FORCE $(Q)$(MAKE) $(build)=gpio-utils -- 2.21.1

4 years, 9 months

3
2
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[PATCH 01/11] rtc: max8907: add missing select REGMAP_IRQ

by Jules Irenge

From: Corentin Labbe <clabbe(a)baylibre.com> I have hit the following build error: armv7a-hardfloat-linux-gnueabi-ld: drivers/rtc/rtc-max8907.o: in function `max8907_rtc_probe': rtc-max8907.c:(.text+0x400): undefined reference to `regmap_irq_get_virq' max8907 should select REGMAP_IRQ Fixes: 94c01ab6d7544 ("rtc: add MAX8907 RTC driver") Cc: stable <stable(a)vger.kernel.org> Signed-off-by: Corentin Labbe <clabbe(a)baylibre.com> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> --- drivers/rtc/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 34c8b6c7e095..8e503881d9d6 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -327,6 +327,7 @@ config RTC_DRV_MAX6900 config RTC_DRV_MAX8907 tristate "Maxim MAX8907" depends on MFD_MAX8907 || COMPILE_TEST + select REGMAP_IRQ help If you say yes here you will get support for the RTC of Maxim MAX8907 PMIC. -- 2.25.1

4 years, 9 months

1
1
0 0

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