From: Jia-Ju Bai <baijiaju1990(a)gmail.com>
[ Upstream commit 3e4272b9954094907f16861199728f14002fcaf6 ]
In a previous commit 7433632c9ff6, buffer, buffer->buffers and
buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL,
and thus the related checks are added.
However, in the same call stack, these variables are also used in
ring_buffer_free_read_page():
tracing_buffers_release()
ring_buffer_wake_waiters(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit
ring_buffer_free_read_page(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> No check
Thus, to avod possible null-pointer derefernces, the related checks
should be added.
These results are reported by a static tool designed by myself.
Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com
Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990(a)gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
kernel/trace/ring_buffer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index c366a0a9ddba4..45d4a23d60444 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -5626,11 +5626,16 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
*/
void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data)
{
- struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+ struct ring_buffer_per_cpu *cpu_buffer;
struct buffer_data_page *bpage = data;
struct page *page = virt_to_page(bpage);
unsigned long flags;
+ if (!buffer || !buffer->buffers || !buffer->buffers[cpu])
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+
/* If the page is still in use someplace else, we can't reuse it */
if (page_ref_count(page) > 1)
goto out;
--
2.39.2
The memcpy() will unconditionally copy PAGE_SIZE bytes, which far exceeds
the length of the array (96 bytes) that it's copying from. You can't
see the results using read() because it'll be limmited by i_size (which
is less than 96 bytes), but if you mmap the file, you can load the bytes
from the page which are beyond i_size. We need to zero the tail of the
page before marking it uptodate.
Cc: stable(a)vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") # actually v2.4.4.4
Signed-off-by: Matthew Wilcox (Oracle) <willy(a)infradead.org>
---
fs/freevxfs/vxfs_immed.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/fs/freevxfs/vxfs_immed.c b/fs/freevxfs/vxfs_immed.c
index 9b49ec36e667..c49612a24c18 100644
--- a/fs/freevxfs/vxfs_immed.c
+++ b/fs/freevxfs/vxfs_immed.c
@@ -30,15 +30,12 @@
*/
static int vxfs_immed_read_folio(struct file *fp, struct folio *folio)
{
- struct vxfs_inode_info *vip = VXFS_INO(folio->mapping->host);
- void *src = vip->vii_immed.vi_immed + folio_pos(folio);
- unsigned long i;
-
- for (i = 0; i < folio_nr_pages(folio); i++) {
- memcpy_to_page(folio_page(folio, i), 0, src, PAGE_SIZE);
- src += PAGE_SIZE;
- }
+ struct inode *inode = folio->mapping->host;
+ struct vxfs_inode_info *vip = VXFS_INO(inode);
+ loff_t isize = i_size_read(inode);
+ memcpy_to_file_folio(folio, 0, vip->vii_immed.vi_immed, isize);
+ folio_zero_segment(folio, isize, folio_size(folio));
folio_mark_uptodate(folio);
folio_unlock(folio);
--
2.39.1
From: Jia-Ju Bai <baijiaju1990(a)gmail.com>
[ Upstream commit 3e4272b9954094907f16861199728f14002fcaf6 ]
In a previous commit 7433632c9ff6, buffer, buffer->buffers and
buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL,
and thus the related checks are added.
However, in the same call stack, these variables are also used in
ring_buffer_free_read_page():
tracing_buffers_release()
ring_buffer_wake_waiters(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit
ring_buffer_free_read_page(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> No check
Thus, to avod possible null-pointer derefernces, the related checks
should be added.
These results are reported by a static tool designed by myself.
Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com
Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990(a)gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
kernel/trace/ring_buffer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 999dae39f12e5..a7808f8b6f56a 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4554,11 +4554,16 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
*/
void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data)
{
- struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+ struct ring_buffer_per_cpu *cpu_buffer;
struct buffer_data_page *bpage = data;
struct page *page = virt_to_page(bpage);
unsigned long flags;
+ if (!buffer || !buffer->buffers || !buffer->buffers[cpu])
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+
/* If the page is still in use someplace else, we can't reuse it */
if (page_ref_count(page) > 1)
goto out;
--
2.39.2
From: Jia-Ju Bai <baijiaju1990(a)gmail.com>
[ Upstream commit 3e4272b9954094907f16861199728f14002fcaf6 ]
In a previous commit 7433632c9ff6, buffer, buffer->buffers and
buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL,
and thus the related checks are added.
However, in the same call stack, these variables are also used in
ring_buffer_free_read_page():
tracing_buffers_release()
ring_buffer_wake_waiters(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit
ring_buffer_free_read_page(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> No check
Thus, to avod possible null-pointer derefernces, the related checks
should be added.
These results are reported by a static tool designed by myself.
Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com
Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990(a)gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
kernel/trace/ring_buffer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 5e5b0c067f611..bef3d01b8ff61 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4685,11 +4685,16 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
*/
void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data)
{
- struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+ struct ring_buffer_per_cpu *cpu_buffer;
struct buffer_data_page *bpage = data;
struct page *page = virt_to_page(bpage);
unsigned long flags;
+ if (!buffer || !buffer->buffers || !buffer->buffers[cpu])
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+
/* If the page is still in use someplace else, we can't reuse it */
if (page_ref_count(page) > 1)
goto out;
--
2.39.2
From: Jia-Ju Bai <baijiaju1990(a)gmail.com>
[ Upstream commit 3e4272b9954094907f16861199728f14002fcaf6 ]
In a previous commit 7433632c9ff6, buffer, buffer->buffers and
buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL,
and thus the related checks are added.
However, in the same call stack, these variables are also used in
ring_buffer_free_read_page():
tracing_buffers_release()
ring_buffer_wake_waiters(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit
ring_buffer_free_read_page(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> No check
Thus, to avod possible null-pointer derefernces, the related checks
should be added.
These results are reported by a static tool designed by myself.
Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com
Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990(a)gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
kernel/trace/ring_buffer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 11e8189dd8ae9..58809fffc8171 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4769,11 +4769,16 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
*/
void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data)
{
- struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+ struct ring_buffer_per_cpu *cpu_buffer;
struct buffer_data_page *bpage = data;
struct page *page = virt_to_page(bpage);
unsigned long flags;
+ if (!buffer || !buffer->buffers || !buffer->buffers[cpu])
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+
/* If the page is still in use someplace else, we can't reuse it */
if (page_ref_count(page) > 1)
goto out;
--
2.39.2
From: Jia-Ju Bai <baijiaju1990(a)gmail.com>
[ Upstream commit 3e4272b9954094907f16861199728f14002fcaf6 ]
In a previous commit 7433632c9ff6, buffer, buffer->buffers and
buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL,
and thus the related checks are added.
However, in the same call stack, these variables are also used in
ring_buffer_free_read_page():
tracing_buffers_release()
ring_buffer_wake_waiters(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit
ring_buffer_free_read_page(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> No check
Thus, to avod possible null-pointer derefernces, the related checks
should be added.
These results are reported by a static tool designed by myself.
Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com
Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990(a)gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
kernel/trace/ring_buffer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 49ebb8c662682..1429d190752ee 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -5324,11 +5324,16 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
*/
void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data)
{
- struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+ struct ring_buffer_per_cpu *cpu_buffer;
struct buffer_data_page *bpage = data;
struct page *page = virt_to_page(bpage);
unsigned long flags;
+ if (!buffer || !buffer->buffers || !buffer->buffers[cpu])
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+
/* If the page is still in use someplace else, we can't reuse it */
if (page_ref_count(page) > 1)
goto out;
--
2.39.2
From: Jia-Ju Bai <baijiaju1990(a)gmail.com>
[ Upstream commit 3e4272b9954094907f16861199728f14002fcaf6 ]
In a previous commit 7433632c9ff6, buffer, buffer->buffers and
buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL,
and thus the related checks are added.
However, in the same call stack, these variables are also used in
ring_buffer_free_read_page():
tracing_buffers_release()
ring_buffer_wake_waiters(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit
ring_buffer_free_read_page(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> No check
Thus, to avod possible null-pointer derefernces, the related checks
should be added.
These results are reported by a static tool designed by myself.
Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com
Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990(a)gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
kernel/trace/ring_buffer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index ffc8696e67467..41ed07e2cbc05 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -5568,11 +5568,16 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
*/
void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data)
{
- struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+ struct ring_buffer_per_cpu *cpu_buffer;
struct buffer_data_page *bpage = data;
struct page *page = virt_to_page(bpage);
unsigned long flags;
+ if (!buffer || !buffer->buffers || !buffer->buffers[cpu])
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+
/* If the page is still in use someplace else, we can't reuse it */
if (page_ref_count(page) > 1)
goto out;
--
2.39.2
From: Jia-Ju Bai <baijiaju1990(a)gmail.com>
[ Upstream commit 3e4272b9954094907f16861199728f14002fcaf6 ]
In a previous commit 7433632c9ff6, buffer, buffer->buffers and
buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL,
and thus the related checks are added.
However, in the same call stack, these variables are also used in
ring_buffer_free_read_page():
tracing_buffers_release()
ring_buffer_wake_waiters(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit
ring_buffer_free_read_page(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> No check
Thus, to avod possible null-pointer derefernces, the related checks
should be added.
These results are reported by a static tool designed by myself.
Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com
Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990(a)gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
kernel/trace/ring_buffer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index b21bf14bae9bd..2a5856ac25ebe 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -5610,11 +5610,16 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
*/
void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data)
{
- struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+ struct ring_buffer_per_cpu *cpu_buffer;
struct buffer_data_page *bpage = data;
struct page *page = virt_to_page(bpage);
unsigned long flags;
+ if (!buffer || !buffer->buffers || !buffer->buffers[cpu])
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+
/* If the page is still in use someplace else, we can't reuse it */
if (page_ref_count(page) > 1)
goto out;
--
2.39.2
From: Valentin Schneider <vschneid(a)redhat.com>
commit 7bb5da0d490b2d836c5218f5186ee588d2145310 upstream.
Patch series "kexec, panic: Making crash_kexec() NMI safe", v4.
This patch (of 2):
Most acquistions of kexec_mutex are done via mutex_trylock() - those were
a direct "translation" from:
8c5a1cf0ad3a ("kexec: use a mutex for locking rather than xchg()")
there have however been two additions since then that use mutex_lock():
crash_get_memory_size() and crash_shrink_memory().
A later commit will replace said mutex with an atomic variable, and
locking operations will become atomic_cmpxchg(). Rather than having those
mutex_lock() become while (atomic_cmpxchg(&lock, 0, 1)), turn them into
trylocks that can return -EBUSY on acquisition failure.
This does halve the printable size of the crash kernel, but that's still
neighbouring 2G for 32bit kernels which should be ample enough.
Link: https://lkml.kernel.org/r/20220630223258.4144112-1-vschneid@redhat.com
Link: https://lkml.kernel.org/r/20220630223258.4144112-2-vschneid@redhat.com
Signed-off-by: Valentin Schneider <vschneid(a)redhat.com>
Cc: Arnd Bergmann <arnd(a)arndb.de>
Cc: "Eric W . Biederman" <ebiederm(a)xmission.com>
Cc: Juri Lelli <jlelli(a)redhat.com>
Cc: Luis Claudio R. Goncalves <lgoncalv(a)redhat.com>
Cc: Miaohe Lin <linmiaohe(a)huawei.com>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Baoquan He <bhe(a)redhat.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Cc: stable(a)vger.kernel.org # 5.10+
Signed-off-by: Wen Yang <wenyang.linux(a)foxmail.com>
---
include/linux/kexec.h | 2 +-
kernel/kexec_core.c | 12 ++++++++----
kernel/ksysfs.c | 7 ++++++-
3 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index a1f12e959bba..3c1deba496c9 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -380,8 +380,8 @@ extern note_buf_t __percpu *crash_notes;
extern bool kexec_in_progress;
int crash_shrink_memory(unsigned long new_size);
-size_t crash_get_memory_size(void);
void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
+ssize_t crash_get_memory_size(void);
void arch_kexec_protect_crashkres(void);
void arch_kexec_unprotect_crashkres(void);
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index c589c7a9562c..e47870f30728 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -989,13 +989,16 @@ void crash_kexec(struct pt_regs *regs)
}
}
-size_t crash_get_memory_size(void)
+ssize_t crash_get_memory_size(void)
{
- size_t size = 0;
+ ssize_t size = 0;
+
+ if (!mutex_trylock(&kexec_mutex))
+ return -EBUSY;
- mutex_lock(&kexec_mutex);
if (crashk_res.end != crashk_res.start)
size = resource_size(&crashk_res);
+
mutex_unlock(&kexec_mutex);
return size;
}
@@ -1016,7 +1019,8 @@ int crash_shrink_memory(unsigned long new_size)
unsigned long old_size;
struct resource *ram_res;
- mutex_lock(&kexec_mutex);
+ if (!mutex_trylock(&kexec_mutex))
+ return -EBUSY;
if (kexec_crash_image) {
ret = -ENOENT;
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 35859da8bd4f..e20c19e3ba49 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -106,7 +106,12 @@ KERNEL_ATTR_RO(kexec_crash_loaded);
static ssize_t kexec_crash_size_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%zu\n", crash_get_memory_size());
+ ssize_t size = crash_get_memory_size();
+
+ if (size < 0)
+ return size;
+
+ return sprintf(buf, "%zd\n", size);
}
static ssize_t kexec_crash_size_store(struct kobject *kobj,
struct kobj_attribute *attr,
--
2.37.2