[PATCH AUTOSEL 4.9 1/8] tty: serial: Fix refcount leak bug in ucc_uart.c

[PATCH AUTOSEL 4.9 1/8] tty: serial: Fix refcount leak bug in ucc_uart.c

[Sasha Levin]

From: Liang He <windhl@126.com>

[ Upstream commit d24d7bb2cd947676f9b71fb944d045e09b8b282f ]

In soc_info(), of_find_node_by_type() will return a node pointer
with refcount incremented. We should use of_node_put() when it is
not used anymore.

Acked-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Liang He <windhl@126.com>
Link: https://lore.kernel.org/r/20220618060850.4058525-1-windhl@126.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/ucc_uart.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
index 481eb2989a1e..ed1658b61e54 100644
--- a/drivers/tty/serial/ucc_uart.c
+++ b/drivers/tty/serial/ucc_uart.c
@@ -1143,6 +1143,8 @@ static unsigned int soc_info(unsigned int *rev_h, unsigned int *rev_l)
 		/* No compatible property, so try the name. */
 		soc_string = np->name;
 
+	of_node_put(np);
+
 	/* Extract the SOC number from the "PowerPC," string */
 	if ((sscanf(soc_string, "PowerPC,%u", &soc) != 1) || !soc)
 		return 0;
-- 
2.35.1

[PATCH AUTOSEL 4.9 2/8] vfio: Clear the caps->buf to NULL after free

[Sasha Levin]

From: Schspa Shi <schspa@gmail.com>

[ Upstream commit 6641085e8d7b3f061911517f79a2a15a0a21b97b ]

On buffer resize failure, vfio_info_cap_add() will free the buffer,
report zero for the size, and return -ENOMEM.  As additional
hardening, also clear the buffer pointer to prevent any chance of a
double free.

Signed-off-by: Schspa Shi <schspa@gmail.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20220629022948.55608-1-schspa@gmail.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/vfio/vfio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 881fc3a55edc..5798965f42b5 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1793,6 +1793,7 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
 	buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
 	if (!buf) {
 		kfree(caps->buf);
+		caps->buf = NULL;
 		caps->size = 0;
 		return ERR_PTR(-ENOMEM);
 	}
-- 
2.35.1

[PATCH AUTOSEL 4.9 3/8] mips: cavium-octeon: Fix missing of_node_put() in octeon2_usb_clocks_start

[Sasha Levin]

From: Liang He <windhl@126.com>

[ Upstream commit 7a9f743ceead60ed454c46fbc3085ee9a79cbebb ]

We should call of_node_put() for the reference 'uctl_node' returned by
of_get_parent() which will increase the refcount. Otherwise, there will
be a refcount leak bug.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/cavium-octeon/octeon-platform.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/mips/cavium-octeon/octeon-platform.c b/arch/mips/cavium-octeon/octeon-platform.c
index 2ecc8d1b0539..f295be876390 100644
--- a/arch/mips/cavium-octeon/octeon-platform.c
+++ b/arch/mips/cavium-octeon/octeon-platform.c
@@ -130,11 +130,12 @@ static void octeon2_usb_clocks_start(struct device *dev)
 					 "refclk-frequency", &clock_rate);
 		if (i) {
 			dev_err(dev, "No UCTL \"refclk-frequency\"\n");
+			of_node_put(uctl_node);
 			goto exit;
 		}
 		i = of_property_read_string(uctl_node,
 					    "refclk-type", &clock_type);
-
+		of_node_put(uctl_node);
 		if (!i && strcmp("crystal", clock_type) == 0)
 			is_crystal_clock = true;
 	}
-- 
2.35.1

[PATCH AUTOSEL 4.9 4/8] ALSA: core: Add async signal helpers

[Sasha Levin]

From: Takashi Iwai <tiwai@suse.de>

[ Upstream commit ef34a0ae7a2654bc9e58675e36898217fb2799d8 ]

Currently the call of kill_fasync() from an interrupt handler might
lead to potential spin deadlocks, as spotted by syzkaller.
Unfortunately, it's not so trivial to fix this lock chain as it's
involved with the tasklist_lock that is touched in allover places.

As a temporary workaround, this patch provides the way to defer the
async signal notification in a work.  The new helper functions,
snd_fasync_helper() and snd_kill_faync() are replacements for
fasync_helper() and kill_fasync(), respectively.  In addition,
snd_fasync_free() needs to be called at the destructor of the relevant
file object.

Link: https://lore.kernel.org/r/20220728125945.29533-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/sound/core.h |  8 ++++
 sound/core/misc.c    | 94 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 102 insertions(+)

diff --git a/include/sound/core.h b/include/sound/core.h
index 31079ea5e484..d5d0e5e53920 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -457,4 +457,12 @@ snd_pci_quirk_lookup_id(u16 vendor, u16 device,
 }
 #endif
 
+/* async signal helpers */
+struct snd_fasync;
+
+int snd_fasync_helper(int fd, struct file *file, int on,
+		      struct snd_fasync **fasyncp);
+void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll);
+void snd_fasync_free(struct snd_fasync *fasync);
+
 #endif /* __SOUND_CORE_H */
diff --git a/sound/core/misc.c b/sound/core/misc.c
index f2e8226c88fb..efe26b8ca57f 100644
--- a/sound/core/misc.c
+++ b/sound/core/misc.c
@@ -25,6 +25,7 @@
 #include <linux/time.h>
 #include <linux/slab.h>
 #include <linux/ioport.h>
+#include <linux/fs.h>
 #include <sound/core.h>
 
 #ifdef CONFIG_SND_DEBUG
@@ -153,3 +154,96 @@ snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list)
 }
 EXPORT_SYMBOL(snd_pci_quirk_lookup);
 #endif
+
+/*
+ * Deferred async signal helpers
+ *
+ * Below are a few helper functions to wrap the async signal handling
+ * in the deferred work.  The main purpose is to avoid the messy deadlock
+ * around tasklist_lock and co at the kill_fasync() invocation.
+ * fasync_helper() and kill_fasync() are replaced with snd_fasync_helper()
+ * and snd_kill_fasync(), respectively.  In addition, snd_fasync_free() has
+ * to be called at releasing the relevant file object.
+ */
+struct snd_fasync {
+	struct fasync_struct *fasync;
+	int signal;
+	int poll;
+	int on;
+	struct list_head list;
+};
+
+static DEFINE_SPINLOCK(snd_fasync_lock);
+static LIST_HEAD(snd_fasync_list);
+
+static void snd_fasync_work_fn(struct work_struct *work)
+{
+	struct snd_fasync *fasync;
+
+	spin_lock_irq(&snd_fasync_lock);
+	while (!list_empty(&snd_fasync_list)) {
+		fasync = list_first_entry(&snd_fasync_list, struct snd_fasync, list);
+		list_del_init(&fasync->list);
+		spin_unlock_irq(&snd_fasync_lock);
+		if (fasync->on)
+			kill_fasync(&fasync->fasync, fasync->signal, fasync->poll);
+		spin_lock_irq(&snd_fasync_lock);
+	}
+	spin_unlock_irq(&snd_fasync_lock);
+}
+
+static DECLARE_WORK(snd_fasync_work, snd_fasync_work_fn);
+
+int snd_fasync_helper(int fd, struct file *file, int on,
+		      struct snd_fasync **fasyncp)
+{
+	struct snd_fasync *fasync = NULL;
+
+	if (on) {
+		fasync = kzalloc(sizeof(*fasync), GFP_KERNEL);
+		if (!fasync)
+			return -ENOMEM;
+		INIT_LIST_HEAD(&fasync->list);
+	}
+
+	spin_lock_irq(&snd_fasync_lock);
+	if (*fasyncp) {
+		kfree(fasync);
+		fasync = *fasyncp;
+	} else {
+		if (!fasync) {
+			spin_unlock_irq(&snd_fasync_lock);
+			return 0;
+		}
+		*fasyncp = fasync;
+	}
+	fasync->on = on;
+	spin_unlock_irq(&snd_fasync_lock);
+	return fasync_helper(fd, file, on, &fasync->fasync);
+}
+EXPORT_SYMBOL_GPL(snd_fasync_helper);
+
+void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll)
+{
+	unsigned long flags;
+
+	if (!fasync || !fasync->on)
+		return;
+	spin_lock_irqsave(&snd_fasync_lock, flags);
+	fasync->signal = signal;
+	fasync->poll = poll;
+	list_move(&fasync->list, &snd_fasync_list);
+	schedule_work(&snd_fasync_work);
+	spin_unlock_irqrestore(&snd_fasync_lock, flags);
+}
+EXPORT_SYMBOL_GPL(snd_kill_fasync);
+
+void snd_fasync_free(struct snd_fasync *fasync)
+{
+	if (!fasync)
+		return;
+	fasync->on = 0;
+	flush_work(&snd_fasync_work);
+	kfree(fasync);
+}
+EXPORT_SYMBOL_GPL(snd_fasync_free);
-- 
2.35.1

[PATCH AUTOSEL 4.9 5/8] ALSA: timer: Use deferred fasync helper

[Sasha Levin]

From: Takashi Iwai <tiwai@suse.de>

[ Upstream commit 95cc637c1afd83fb7dd3d7c8a53710488f4caf9c ]

For avoiding the potential deadlock via kill_fasync() call, use the
new fasync helpers to defer the invocation from PCI API.  Note that
it's merely a workaround.

Reported-by: syzbot+1ee0910eca9c94f71f25@syzkaller.appspotmail.com
Reported-by: syzbot+49b10793b867871ee26f@syzkaller.appspotmail.com
Reported-by: syzbot+8285e973a41b5aa68902@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20220728125945.29533-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 sound/core/timer.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 596ba572d6c4..1f5f05e76e59 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -74,7 +74,7 @@ struct snd_timer_user {
 	unsigned int filter;
 	struct timespec tstamp;		/* trigger tstamp */
 	wait_queue_head_t qchange_sleep;
-	struct fasync_struct *fasync;
+	struct snd_fasync *fasync;
 	struct mutex ioctl_lock;
 };
 
@@ -1293,7 +1293,7 @@ static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
 	}
       __wake:
 	spin_unlock(&tu->qlock);
-	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
+	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
 	wake_up(&tu->qchange_sleep);
 }
 
@@ -1330,7 +1330,7 @@ static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
 	spin_lock_irqsave(&tu->qlock, flags);
 	snd_timer_user_append_to_tqueue(tu, &r1);
 	spin_unlock_irqrestore(&tu->qlock, flags);
-	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
+	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
 	wake_up(&tu->qchange_sleep);
 }
 
@@ -1397,7 +1397,7 @@ static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
 	spin_unlock(&tu->qlock);
 	if (append == 0)
 		return;
-	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
+	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
 	wake_up(&tu->qchange_sleep);
 }
 
@@ -1439,6 +1439,7 @@ static int snd_timer_user_release(struct inode *inode, struct file *file)
 		if (tu->timeri)
 			snd_timer_close(tu->timeri);
 		mutex_unlock(&tu->ioctl_lock);
+		snd_fasync_free(tu->fasync);
 		kfree(tu->queue);
 		kfree(tu->tqueue);
 		kfree(tu);
@@ -2026,7 +2027,7 @@ static int snd_timer_user_fasync(int fd, struct file * file, int on)
 	struct snd_timer_user *tu;
 
 	tu = file->private_data;
-	return fasync_helper(fd, file, on, &tu->fasync);
+	return snd_fasync_helper(fd, file, on, &tu->fasync);
 }
 
 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
-- 
2.35.1

[PATCH AUTOSEL 4.9 6/8] powerpc/64: Init jump labels before parse_early_param()

[Sasha Levin]

From: Zhouyi Zhou <zhouzhouyi@gmail.com>

[ Upstream commit ca829e05d3d4f728810cc5e4b468d9ebc7745eb3 ]

On 64-bit, calling jump_label_init() in setup_feature_keys() is too
late because static keys may be used in subroutines of
parse_early_param() which is again subroutine of early_init_devtree().

For example booting with "threadirqs":

  static_key_enable_cpuslocked(): static key '0xc000000002953260' used before call to jump_label_init()
  WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:166 static_key_enable_cpuslocked+0xfc/0x120
  ...
  NIP static_key_enable_cpuslocked+0xfc/0x120
  LR  static_key_enable_cpuslocked+0xf8/0x120
  Call Trace:
    static_key_enable_cpuslocked+0xf8/0x120 (unreliable)
    static_key_enable+0x30/0x50
    setup_forced_irqthreads+0x28/0x40
    do_early_param+0xa0/0x108
    parse_args+0x290/0x4e0
    parse_early_options+0x48/0x5c
    parse_early_param+0x58/0x84
    early_init_devtree+0xd4/0x518
    early_setup+0xb4/0x214

So call jump_label_init() just before parse_early_param() in
early_init_devtree().

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
[mpe: Add call trace to change log and minor wording edits.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220726015747.11754-1-zhouzhouyi@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/prom.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 11b4ecec04ee..1413d72689d2 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -682,6 +682,13 @@ void __init early_init_devtree(void *params)
 	of_scan_flat_dt(early_init_dt_scan_root, NULL);
 	of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
 
+	/*
+	 * As generic code authors expect to be able to use static keys
+	 * in early_param() handlers, we initialize the static keys just
+	 * before parsing early params (it's fine to call jump_label_init()
+	 * more than once).
+	 */
+	jump_label_init();
 	parse_early_param();
 
 	/* make sure we've parsed cmdline for mem= before this */
-- 
2.35.1

[PATCH AUTOSEL 4.9 7/8] video: fbdev: i740fb: Check the argument of i740_calc_vclk()

[Sasha Levin]

From: Zheyu Ma <zheyuma97@gmail.com>

[ Upstream commit 40bf722f8064f50200b8c4f8946cd625b441dda9 ]

Since the user can control the arguments of the ioctl() from the user
space, under special arguments that may result in a divide-by-zero bug.

If the user provides an improper 'pixclock' value that makes the argumet
of i740_calc_vclk() less than 'I740_RFREQ_FIX', it will cause a
divide-by-zero bug in:
    drivers/video/fbdev/i740fb.c:353 p_best = min(15, ilog2(I740_MAX_VCO_FREQ / (freq / I740_RFREQ_FIX)));

The following log can reveal it:

divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:i740_calc_vclk drivers/video/fbdev/i740fb.c:353 [inline]
RIP: 0010:i740fb_decode_var drivers/video/fbdev/i740fb.c:646 [inline]
RIP: 0010:i740fb_set_par+0x163f/0x3b70 drivers/video/fbdev/i740fb.c:742
Call Trace:
 fb_set_var+0x604/0xeb0 drivers/video/fbdev/core/fbmem.c:1034
 do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189

Fix this by checking the argument of i740_calc_vclk() first.

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/fbdev/i740fb.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/i740fb.c b/drivers/video/fbdev/i740fb.c
index 7bc5f6056c77..4147a9534179 100644
--- a/drivers/video/fbdev/i740fb.c
+++ b/drivers/video/fbdev/i740fb.c
@@ -399,7 +399,7 @@ static int i740fb_decode_var(const struct fb_var_screeninfo *var,
 	u32 xres, right, hslen, left, xtotal;
 	u32 yres, lower, vslen, upper, ytotal;
 	u32 vxres, xoffset, vyres, yoffset;
-	u32 bpp, base, dacspeed24, mem;
+	u32 bpp, base, dacspeed24, mem, freq;
 	u8 r7;
 	int i;
 
@@ -641,7 +641,12 @@ static int i740fb_decode_var(const struct fb_var_screeninfo *var,
 	par->atc[VGA_ATC_OVERSCAN] = 0;
 
 	/* Calculate VCLK that most closely matches the requested dot clock */
-	i740_calc_vclk((((u32)1e9) / var->pixclock) * (u32)(1e3), par);
+	freq = (((u32)1e9) / var->pixclock) * (u32)(1e3);
+	if (freq < I740_RFREQ_FIX) {
+		fb_dbg(info, "invalid pixclock\n");
+		freq = I740_RFREQ_FIX;
+	}
+	i740_calc_vclk(freq, par);
 
 	/* Since we program the clocks ourselves, always use VCLK2. */
 	par->misc |= 0x0C;
-- 
2.35.1

[PATCH AUTOSEL 4.9 8/8] MIPS: tlbex: Explicitly compare _PAGE_NO_EXEC against 0

[Sasha Levin]

From: Nathan Chancellor <nathan@kernel.org>

[ Upstream commit 74de14fe05dd6b151d73cb0c73c8ec874cbdcde6 ]

When CONFIG_XPA is enabled, Clang warns:

  arch/mips/mm/tlbex.c:629:24: error: converting the result of '<<' to a boolean; did you mean '(1 << _PAGE_NO_EXEC_SHIFT) != 0'? [-Werror,-Wint-in-bool-context]
          if (cpu_has_rixi && !!_PAGE_NO_EXEC) {
                              ^
  arch/mips/include/asm/pgtable-bits.h:174:28: note: expanded from macro '_PAGE_NO_EXEC'
  # define _PAGE_NO_EXEC          (1 << _PAGE_NO_EXEC_SHIFT)
                                     ^
  arch/mips/mm/tlbex.c:2568:24: error: converting the result of '<<' to a boolean; did you mean '(1 << _PAGE_NO_EXEC_SHIFT) != 0'? [-Werror,-Wint-in-bool-context]
          if (!cpu_has_rixi || !_PAGE_NO_EXEC) {
                                ^
  arch/mips/include/asm/pgtable-bits.h:174:28: note: expanded from macro '_PAGE_NO_EXEC'
  # define _PAGE_NO_EXEC          (1 << _PAGE_NO_EXEC_SHIFT)
                                     ^
  2 errors generated.

_PAGE_NO_EXEC can be '0' or '1 << _PAGE_NO_EXEC_SHIFT' depending on the
build and runtime configuration, which is what the negation operators
are trying to convey. To silence the warning, explicitly compare against
0 so the result of the '<<' operator is not implicitly converted to a
boolean.

According to its documentation, GCC enables -Wint-in-bool-context with
-Wall but this warning is not visible when building the same
configuration with GCC. It appears GCC only warns when compiling C++,
not C, although the documentation makes no note of this:
https://godbolt.org/z/x39q3brxf

Reported-by: Sudip Mukherjee (Codethink) <sudipm.mukherjee@gmail.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/mm/tlbex.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index f625fd20b21e..65fed205383e 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -637,7 +637,7 @@ static __maybe_unused void build_convert_pte_to_entrylo(u32 **p,
 		return;
 	}
 
-	if (cpu_has_rixi && !!_PAGE_NO_EXEC) {
+	if (cpu_has_rixi && _PAGE_NO_EXEC != 0) {
 		if (fill_includes_sw_bits) {
 			UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL));
 		} else {
@@ -2518,7 +2518,7 @@ static void check_pabits(void)
 	unsigned long entry;
 	unsigned pabits, fillbits;
 
-	if (!cpu_has_rixi || !_PAGE_NO_EXEC) {
+	if (!cpu_has_rixi || _PAGE_NO_EXEC == 0) {
 		/*
 		 * We'll only be making use of the fact that we can rotate bits
 		 * into the fill if the CPU supports RIXI, so don't bother
-- 
2.35.1