| Message ID | 20250318010448.954-3-chenste@linux.microsoft.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | ima: kexec: measure events between kexec load and execute | expand |
On 03/17/25 at 06:04pm, steven chen wrote: > Carrying the IMA measurement list across kexec requires allocating a > buffer and copying the measurement records. Separate allocating the > buffer and copying the measurement records into separate functions in > order to allocate the buffer at kexec 'load' and copy the measurements > at kexec 'execute'. > > This patch includes the following changes: > - Refactor ima_dump_measurement_list() to move the memory allocation > to a separate function ima_alloc_kexec_file_buf() which allocates > buffer of size 'kexec_segment_size' at kexec 'load'. > - Make the local variable ima_kexec_file in ima_dump_measurement_list() > a local static to the file, so that it can be accessed from > ima_alloc_kexec_file_buf(). > - Make necessary changes to the function ima_add_kexec_buffer() to call > the above two functions. We may not need above details about code change because it's not so difficult to get them from patch. > > Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> > Signed-off-by: steven chen <chenste@linux.microsoft.com> > --- > security/integrity/ima/ima_kexec.c | 67 +++++++++++++++++++++++++----- > 1 file changed, 56 insertions(+), 11 deletions(-) > > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c > index 8567619889d1..45170e283272 100644 > --- a/security/integrity/ima/ima_kexec.c > +++ b/security/integrity/ima/ima_kexec.c > @@ -15,6 +15,48 @@ > #include "ima.h" > > #ifdef CONFIG_IMA_KEXEC > +static struct seq_file ima_kexec_file; > + > +static void ima_reset_kexec_file(struct seq_file *sf) > +{ > + sf->buf = NULL; > + sf->size = 0; > + sf->read_pos = 0; > + sf->count = 0; > +} > + > +static void ima_free_kexec_file_buf(struct seq_file *sf) > +{ > + vfree(sf->buf); > + ima_reset_kexec_file(sf); > +} > + > +static int ima_alloc_kexec_file_buf(size_t segment_size) > +{ > + /* > + * kexec 'load' may be called multiple times. > + * Free and realloc the buffer only if the segment_size is > + * changed from the previous kexec 'load' call. > + */ > + if (ima_kexec_file.buf && ima_kexec_file.size == segment_size) > + goto out; > + > + ima_free_kexec_file_buf(&ima_kexec_file); > + > + /* segment size can't change between kexec load and execute */ > + ima_kexec_file.buf = vmalloc(segment_size); > + if (!ima_kexec_file.buf) > + return -ENOMEM; > + > + ima_kexec_file.size = segment_size; > + > +out: > + ima_kexec_file.read_pos = 0; > + ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ > + > + return 0; > +} > + > /* > * Copy the measurement list to the allocated memory > * compare the size of IMA measurement list with the size of the allocated memory > @@ -26,23 +68,16 @@ > static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > unsigned long segment_size) > { > - struct seq_file ima_kexec_file; > struct ima_queue_entry *qe; > struct ima_kexec_hdr khdr; > int ret = 0; > > /* segment size can't change between kexec load and execute */ > - ima_kexec_file.buf = vmalloc(segment_size); > if (!ima_kexec_file.buf) { > - ret = -ENOMEM; > - goto out; > + pr_err("Kexec file buf not allocated\n"); > + return -EINVAL; > } > > - ima_kexec_file.file = NULL; > - ima_kexec_file.size = segment_size; > - ima_kexec_file.read_pos = 0; > - ima_kexec_file.count = sizeof(khdr); /* reserved space */ > - > memset(&khdr, 0, sizeof(khdr)); > khdr.version = 1; > /* This is an append-only list, no need to hold the RCU read lock */ > @@ -79,8 +114,6 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > *buffer_size = ima_kexec_file.count; > *buffer = ima_kexec_file.buf; > out: > - if (ret == -EINVAL) > - vfree(ima_kexec_file.buf); > return ret; > } > > @@ -119,6 +152,12 @@ void ima_add_kexec_buffer(struct kimage *image) > return; > } > > + ret = ima_alloc_kexec_file_buf(kexec_segment_size); > + if (ret < 0) { > + pr_err("Not enough memory for the kexec measurement buffer.\n"); > + return; > + } > + > ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, > kexec_segment_size); > if (!kexec_buffer) { > @@ -140,6 +179,12 @@ void ima_add_kexec_buffer(struct kimage *image) > image->ima_buffer_size = kexec_segment_size; > image->ima_buffer = kexec_buffer; > > + /* > + * kexec owns kexec_buffer after kexec_add_buffer() is called > + * and it will vfree() that buffer. > + */ > + ima_reset_kexec_file(&ima_kexec_file); I can't see why we need call ima_reset_kexec_file() here. If we need reuse the buffer, we will reset the needed fields at the end of ima_alloc_kexec_file_buf(). Not sure if I miss anything. static int ima_alloc_kexec_file_buf(size_t segment_size) { ...... out: ima_kexec_file.read_pos = 0; ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ return 0; }
On Wed, 2025-03-19 at 16:09 +0800, Baoquan He wrote: > On 03/17/25 at 06:04pm, steven chen wrote: > > Carrying the IMA measurement list across kexec requires allocating a > > buffer and copying the measurement records. Separate allocating the > > buffer and copying the measurement records into separate functions in > > order to allocate the buffer at kexec 'load' and copy the measurements > > at kexec 'execute'. > > > > This patch includes the following changes: > > - Refactor ima_dump_measurement_list() to move the memory allocation > > to a separate function ima_alloc_kexec_file_buf() which allocates > > buffer of size 'kexec_segment_size' at kexec 'load'. > > - Make the local variable ima_kexec_file in ima_dump_measurement_list() > > a local static to the file, so that it can be accessed from > > ima_alloc_kexec_file_buf(). > > - Make necessary changes to the function ima_add_kexec_buffer() to call > > the above two functions. > > We may not need above details about code change because it's not so > difficult to get them from patch. Agreed. The changes don't even reflect the current patch. Please remove the entire section. > > > > > Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> > > Signed-off-by: steven chen <chenste@linux.microsoft.com> > > --- > > security/integrity/ima/ima_kexec.c | 67 +++++++++++++++++++++++++----- > > 1 file changed, 56 insertions(+), 11 deletions(-) > > > > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c > > index 8567619889d1..45170e283272 100644 > > --- a/security/integrity/ima/ima_kexec.c > > +++ b/security/integrity/ima/ima_kexec.c > > @@ -15,6 +15,48 @@ > > #include "ima.h" > > > > #ifdef CONFIG_IMA_KEXEC > > +static struct seq_file ima_kexec_file; > > + > > +static void ima_reset_kexec_file(struct seq_file *sf) > > +{ > > + sf->buf = NULL; > > + sf->size = 0; > > + sf->read_pos = 0; > > + sf->count = 0; > > +} > > + > > +static void ima_free_kexec_file_buf(struct seq_file *sf) > > +{ > > + vfree(sf->buf); > > + ima_reset_kexec_file(sf); > > +} > > + > > +static int ima_alloc_kexec_file_buf(size_t segment_size) > > +{ > > + /* > > + * kexec 'load' may be called multiple times. > > + * Free and realloc the buffer only if the segment_size is > > + * changed from the previous kexec 'load' call. > > + */ > > + if (ima_kexec_file.buf && ima_kexec_file.size == segment_size) > > + goto out; The call to ima_reset_kexec_file() in ima_add_kexec_buffer() resets ima_kexec_file.buf() hiding the fact that the above test always fails and falls through. As a result, 'buf' is always being re-allocated. > > + > > + ima_free_kexec_file_buf(&ima_kexec_file); > > + > > + /* segment size can't change between kexec load and execute */ > > + ima_kexec_file.buf = vmalloc(segment_size); > > + if (!ima_kexec_file.buf) > > + return -ENOMEM; > > + > > + ima_kexec_file.size = segment_size; > > + > > +out: > > + ima_kexec_file.read_pos = 0; > > + ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ > > + > > + return 0; > > +} > > + > > /* > > * Copy the measurement list to the allocated memory > > * compare the size of IMA measurement list with the size of the allocated memory > > @@ -26,23 +68,16 @@ > > static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > > unsigned long segment_size) > > { > > - struct seq_file ima_kexec_file; > > struct ima_queue_entry *qe; > > struct ima_kexec_hdr khdr; > > int ret = 0; > > > > /* segment size can't change between kexec load and execute */ > > - ima_kexec_file.buf = vmalloc(segment_size); > > if (!ima_kexec_file.buf) { > > - ret = -ENOMEM; > > - goto out; > > + pr_err("Kexec file buf not allocated\n"); > > + return -EINVAL; > > } > > > > - ima_kexec_file.file = NULL; > > - ima_kexec_file.size = segment_size; > > - ima_kexec_file.read_pos = 0; > > - ima_kexec_file.count = sizeof(khdr); /* reserved space */ > > - > > memset(&khdr, 0, sizeof(khdr)); > > khdr.version = 1; > > /* This is an append-only list, no need to hold the RCU read lock */ > > @@ -79,8 +114,6 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > > *buffer_size = ima_kexec_file.count; > > *buffer = ima_kexec_file.buf; > > out: > > - if (ret == -EINVAL) > > - vfree(ima_kexec_file.buf); > > return ret; > > } > > > > @@ -119,6 +152,12 @@ void ima_add_kexec_buffer(struct kimage *image) > > return; > > } > > > > + ret = ima_alloc_kexec_file_buf(kexec_segment_size); > > + if (ret < 0) { > > + pr_err("Not enough memory for the kexec measurement buffer.\n"); > > + return; > > + } > > + > > ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, > > kexec_segment_size); > > if (!kexec_buffer) { > > @@ -140,6 +179,12 @@ void ima_add_kexec_buffer(struct kimage *image) > > image->ima_buffer_size = kexec_segment_size; > > image->ima_buffer = kexec_buffer; > > > > + /* > > + * kexec owns kexec_buffer after kexec_add_buffer() is called > > + * and it will vfree() that buffer. > > + */ > > + ima_reset_kexec_file(&ima_kexec_file); > > I can't see why we need call ima_reset_kexec_file() here. If we need > reuse the buffer, we will reset the needed fields at the end of > ima_alloc_kexec_file_buf(). Not sure if I miss anything. Without ima_reset_kexec_file(), calling 'kexec load' consecutively without "kexec -s -e" in between fails. # kexec -s -l /boot/vmlinuz-`uname -r` --initrd=/boot/initramfs-`uname -r`.img --reuse-cmdline # kexec -s -l /boot/vmlinuz-`uname -r` --initrd=/boot/initramfs-`uname -r`.img --reuse-cmdline Killed As mentioned above, the call to ima_reset_kexec_file() resets ima_kexec_file.buf, so the segment size test always fails and the memory is being allocated. Mimi > > static int ima_alloc_kexec_file_buf(size_t segment_size) > { > ...... > out: > ima_kexec_file.read_pos = 0; > ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ > > return 0; > } > >
On 03/19/25 at 12:27pm, Mimi Zohar wrote: > On Wed, 2025-03-19 at 16:09 +0800, Baoquan He wrote: > > On 03/17/25 at 06:04pm, steven chen wrote: > > > Carrying the IMA measurement list across kexec requires allocating a > > > buffer and copying the measurement records. Separate allocating the > > > buffer and copying the measurement records into separate functions in > > > order to allocate the buffer at kexec 'load' and copy the measurements > > > at kexec 'execute'. > > > > > > This patch includes the following changes: > > > - Refactor ima_dump_measurement_list() to move the memory allocation > > > to a separate function ima_alloc_kexec_file_buf() which allocates > > > buffer of size 'kexec_segment_size' at kexec 'load'. > > > - Make the local variable ima_kexec_file in ima_dump_measurement_list() > > > a local static to the file, so that it can be accessed from > > > ima_alloc_kexec_file_buf(). > > > - Make necessary changes to the function ima_add_kexec_buffer() to call > > > the above two functions. > > > > We may not need above details about code change because it's not so > > difficult to get them from patch. > > Agreed. The changes don't even reflect the current patch. Please remove the > entire section. > > > > > > > > > Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> > > > Signed-off-by: steven chen <chenste@linux.microsoft.com> > > > --- > > > security/integrity/ima/ima_kexec.c | 67 +++++++++++++++++++++++++----- > > > 1 file changed, 56 insertions(+), 11 deletions(-) > > > > > > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c > > > index 8567619889d1..45170e283272 100644 > > > --- a/security/integrity/ima/ima_kexec.c > > > +++ b/security/integrity/ima/ima_kexec.c > > > @@ -15,6 +15,48 @@ > > > #include "ima.h" > > > > > > #ifdef CONFIG_IMA_KEXEC > > > +static struct seq_file ima_kexec_file; > > > + > > > +static void ima_reset_kexec_file(struct seq_file *sf) > > > +{ > > > + sf->buf = NULL; > > > + sf->size = 0; > > > + sf->read_pos = 0; > > > + sf->count = 0; > > > +} > > > + > > > +static void ima_free_kexec_file_buf(struct seq_file *sf) > > > +{ > > > + vfree(sf->buf); > > > + ima_reset_kexec_file(sf); > > > +} > > > + > > > +static int ima_alloc_kexec_file_buf(size_t segment_size) > > > +{ > > > + /* > > > + * kexec 'load' may be called multiple times. > > > + * Free and realloc the buffer only if the segment_size is > > > + * changed from the previous kexec 'load' call. > > > + */ > > > + if (ima_kexec_file.buf && ima_kexec_file.size == segment_size) > > > + goto out; > > The call to ima_reset_kexec_file() in ima_add_kexec_buffer() resets > ima_kexec_file.buf() hiding the fact that the above test always fails and falls > through. As a result, 'buf' is always being re-allocated. > > > > + > > > + ima_free_kexec_file_buf(&ima_kexec_file); > > > + > > > + /* segment size can't change between kexec load and execute */ > > > + ima_kexec_file.buf = vmalloc(segment_size); > > > + if (!ima_kexec_file.buf) > > > + return -ENOMEM; > > > + > > > + ima_kexec_file.size = segment_size; > > > + > > > +out: > > > + ima_kexec_file.read_pos = 0; > > > + ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ > > > + > > > + return 0; > > > +} > > > + > > > /* > > > * Copy the measurement list to the allocated memory > > > * compare the size of IMA measurement list with the size of the allocated memory > > > @@ -26,23 +68,16 @@ > > > static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > > > unsigned long segment_size) > > > { > > > - struct seq_file ima_kexec_file; > > > struct ima_queue_entry *qe; > > > struct ima_kexec_hdr khdr; > > > int ret = 0; > > > > > > /* segment size can't change between kexec load and execute */ > > > - ima_kexec_file.buf = vmalloc(segment_size); > > > if (!ima_kexec_file.buf) { > > > - ret = -ENOMEM; > > > - goto out; > > > + pr_err("Kexec file buf not allocated\n"); > > > + return -EINVAL; > > > } > > > > > > - ima_kexec_file.file = NULL; > > > - ima_kexec_file.size = segment_size; > > > - ima_kexec_file.read_pos = 0; > > > - ima_kexec_file.count = sizeof(khdr); /* reserved space */ > > > - > > > memset(&khdr, 0, sizeof(khdr)); > > > khdr.version = 1; > > > /* This is an append-only list, no need to hold the RCU read lock */ > > > @@ -79,8 +114,6 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > > > *buffer_size = ima_kexec_file.count; > > > *buffer = ima_kexec_file.buf; > > > out: > > > - if (ret == -EINVAL) > > > - vfree(ima_kexec_file.buf); > > > return ret; > > > } > > > > > > @@ -119,6 +152,12 @@ void ima_add_kexec_buffer(struct kimage *image) > > > return; > > > } > > > > > > + ret = ima_alloc_kexec_file_buf(kexec_segment_size); > > > + if (ret < 0) { > > > + pr_err("Not enough memory for the kexec measurement buffer.\n"); > > > + return; > > > + } > > > + > > > ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, > > > kexec_segment_size); > > > if (!kexec_buffer) { > > > @@ -140,6 +179,12 @@ void ima_add_kexec_buffer(struct kimage *image) > > > image->ima_buffer_size = kexec_segment_size; > > > image->ima_buffer = kexec_buffer; > > > > > > + /* > > > + * kexec owns kexec_buffer after kexec_add_buffer() is called > > > + * and it will vfree() that buffer. > > > + */ > > > + ima_reset_kexec_file(&ima_kexec_file); > > > > I can't see why we need call ima_reset_kexec_file() here. If we need > > reuse the buffer, we will reset the needed fields at the end of > > ima_alloc_kexec_file_buf(). Not sure if I miss anything. > > Without ima_reset_kexec_file(), calling 'kexec load' consecutively without > "kexec -s -e" in between fails. > > # kexec -s -l /boot/vmlinuz-`uname -r` --initrd=/boot/initramfs-`uname -r`.img --reuse-cmdline > # kexec -s -l /boot/vmlinuz-`uname -r` --initrd=/boot/initramfs-`uname -r`.img --reuse-cmdline > Killed > > As mentioned above, the call to ima_reset_kexec_file() resets > ima_kexec_file.buf, so the segment size test always fails and the memory is > being allocated. Indeed, I didn't realize this.
On Thu, 2025-03-20 at 09:51 +0800, Baoquan He wrote: > > > > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c > > > > index 8567619889d1..45170e283272 100644 > > > > --- a/security/integrity/ima/ima_kexec.c > > > > +++ b/security/integrity/ima/ima_kexec.c > > > > @@ -15,6 +15,48 @@ > > > > #include "ima.h" > > > > > > > > #ifdef CONFIG_IMA_KEXEC > > > > +static struct seq_file ima_kexec_file; > > > > + > > > > +static void ima_reset_kexec_file(struct seq_file *sf) > > > > +{ > > > > + sf->buf = NULL; > > > > + sf->size = 0; > > > > + sf->read_pos = 0; > > > > + sf->count = 0; > > > > +} > > > > + > > > > +static void ima_free_kexec_file_buf(struct seq_file *sf) > > > > +{ > > > > + vfree(sf->buf); > > > > + ima_reset_kexec_file(sf); > > > > +} > > > > + > > > > +static int ima_alloc_kexec_file_buf(size_t segment_size) > > > > +{ > > > > + /* > > > > + * kexec 'load' may be called multiple times. > > > > + * Free and realloc the buffer only if the segment_size is > > > > + * changed from the previous kexec 'load' call. > > > > + */ > > > > + if (ima_kexec_file.buf && ima_kexec_file.size == segment_size) > > > > + goto out; > > > > The call to ima_reset_kexec_file() in ima_add_kexec_buffer() resets > > ima_kexec_file.buf() hiding the fact that the above test always fails and falls > > through. As a result, 'buf' is always being re-allocated. Hi Steven, [Reiterating the comment in the "ima: kexec: move IMA log copy from kexec load to execute" thread, here, for completeness.] Instead of adding and then removing the ima_reset_kexec_file() call from ima_add_kexec_buffer(), defer adding the segment size test to when it is actually possible for the segment size to change. Please make the segment size test as a separate patch. ima_reset_kexec_file() will then only be called by ima_free_kexec_file_buf(). Inline the ima_reset_kexec_file() code in ima_free_kexec_file_buf(). thanks, Mimi
On 3/20/2025 6:06 AM, Mimi Zohar wrote: > On Thu, 2025-03-20 at 09:51 +0800, Baoquan He wrote: >>>>> diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c >>>>> index 8567619889d1..45170e283272 100644 >>>>> --- a/security/integrity/ima/ima_kexec.c >>>>> +++ b/security/integrity/ima/ima_kexec.c >>>>> @@ -15,6 +15,48 @@ >>>>> #include "ima.h" >>>>> >>>>> #ifdef CONFIG_IMA_KEXEC >>>>> +static struct seq_file ima_kexec_file; >>>>> + >>>>> +static void ima_reset_kexec_file(struct seq_file *sf) >>>>> +{ >>>>> + sf->buf = NULL; >>>>> + sf->size = 0; >>>>> + sf->read_pos = 0; >>>>> + sf->count = 0; >>>>> +} >>>>> + >>>>> +static void ima_free_kexec_file_buf(struct seq_file *sf) >>>>> +{ >>>>> + vfree(sf->buf); >>>>> + ima_reset_kexec_file(sf); >>>>> +} >>>>> + >>>>> +static int ima_alloc_kexec_file_buf(size_t segment_size) >>>>> +{ >>>>> + /* >>>>> + * kexec 'load' may be called multiple times. >>>>> + * Free and realloc the buffer only if the segment_size is >>>>> + * changed from the previous kexec 'load' call. >>>>> + */ >>>>> + if (ima_kexec_file.buf && ima_kexec_file.size == segment_size) >>>>> + goto out; >>> The call to ima_reset_kexec_file() in ima_add_kexec_buffer() resets >>> ima_kexec_file.buf() hiding the fact that the above test always fails and falls >>> through. As a result, 'buf' is always being re-allocated. > Hi Steven, > > [Reiterating the comment in the "ima: kexec: move IMA log copy from kexec load > to execute" thread, here, for completeness.] > > Instead of adding and then removing the ima_reset_kexec_file() call from > ima_add_kexec_buffer(), defer adding the segment size test to when it is > actually possible for the segment size to change. Please make the segment size > test as a separate patch. > > ima_reset_kexec_file() will then only be called by ima_free_kexec_file_buf(). > Inline the ima_reset_kexec_file() code in ima_free_kexec_file_buf(). > > thanks, > > Mimi Hi Mimi, I will update in next version. Thanks, Steven
diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 8567619889d1..45170e283272 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -15,6 +15,48 @@ #include "ima.h" #ifdef CONFIG_IMA_KEXEC +static struct seq_file ima_kexec_file; + +static void ima_reset_kexec_file(struct seq_file *sf) +{ + sf->buf = NULL; + sf->size = 0; + sf->read_pos = 0; + sf->count = 0; +} + +static void ima_free_kexec_file_buf(struct seq_file *sf) +{ + vfree(sf->buf); + ima_reset_kexec_file(sf); +} + +static int ima_alloc_kexec_file_buf(size_t segment_size) +{ + /* + * kexec 'load' may be called multiple times. + * Free and realloc the buffer only if the segment_size is + * changed from the previous kexec 'load' call. + */ + if (ima_kexec_file.buf && ima_kexec_file.size == segment_size) + goto out; + + ima_free_kexec_file_buf(&ima_kexec_file); + + /* segment size can't change between kexec load and execute */ + ima_kexec_file.buf = vmalloc(segment_size); + if (!ima_kexec_file.buf) + return -ENOMEM; + + ima_kexec_file.size = segment_size; + +out: + ima_kexec_file.read_pos = 0; + ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ + + return 0; +} + /* * Copy the measurement list to the allocated memory * compare the size of IMA measurement list with the size of the allocated memory @@ -26,23 +68,16 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, unsigned long segment_size) { - struct seq_file ima_kexec_file; struct ima_queue_entry *qe; struct ima_kexec_hdr khdr; int ret = 0; /* segment size can't change between kexec load and execute */ - ima_kexec_file.buf = vmalloc(segment_size); if (!ima_kexec_file.buf) { - ret = -ENOMEM; - goto out; + pr_err("Kexec file buf not allocated\n"); + return -EINVAL; } - ima_kexec_file.file = NULL; - ima_kexec_file.size = segment_size; - ima_kexec_file.read_pos = 0; - ima_kexec_file.count = sizeof(khdr); /* reserved space */ - memset(&khdr, 0, sizeof(khdr)); khdr.version = 1; /* This is an append-only list, no need to hold the RCU read lock */ @@ -79,8 +114,6 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, *buffer_size = ima_kexec_file.count; *buffer = ima_kexec_file.buf; out: - if (ret == -EINVAL) - vfree(ima_kexec_file.buf); return ret; } @@ -119,6 +152,12 @@ void ima_add_kexec_buffer(struct kimage *image) return; } + ret = ima_alloc_kexec_file_buf(kexec_segment_size); + if (ret < 0) { + pr_err("Not enough memory for the kexec measurement buffer.\n"); + return; + } + ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, kexec_segment_size); if (!kexec_buffer) { @@ -140,6 +179,12 @@ void ima_add_kexec_buffer(struct kimage *image) image->ima_buffer_size = kexec_segment_size; image->ima_buffer = kexec_buffer; + /* + * kexec owns kexec_buffer after kexec_add_buffer() is called + * and it will vfree() that buffer. + */ + ima_reset_kexec_file(&ima_kexec_file); + kexec_dprintk("kexec measurement buffer for the loaded kernel at 0x%lx.\n", kbuf.mem); }