[PATCH V5] Fix NULL dereference in super_by_fd

[PATCH V5] Fix NULL dereference in super_by_fd

[Li Xiao Keng]

When we create 100 partitions (major is 259 not 254) in a raid device,
mdadm may coredump:

Core was generated by `/usr/sbin/mdadm --detail --export /dev/md1p7'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  __strlen_avx2_rtm () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
74		VPCMPEQ	(%rdi), %ymm0, %ymm1
(gdb) bt
#0  __strlen_avx2_rtm () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
#1  0x00007fbb9a7e4139 in __strcpy_chk (dest=dest@entry=0x55d55d6a13ac "", src=0x0, destlen=destlen@entry=32) at strcpy_chk.c:28
#2  0x000055d55ba1766d in strcpy (__src=<optimized out>, __dest=0x55d55d6a13ac "") at /usr/include/bits/string_fortified.h:79
#3  super_by_fd (fd=fd@entry=3, subarrayp=subarrayp@entry=0x7fff44dfcc48) at util.c:1289
#4  0x000055d55ba273a6 in Detail (dev=0x7fff44dfef0b "/dev/md1p7", c=0x7fff44dfe440) at Detail.c:101
#5  0x000055d55ba0de61 in misc_list (c=<optimized out>, ss=<optimized out>, dump_directory=<optimized out>, ident=<optimized out>, devlist=<optimized out>) at mdadm.c:1959
#6  main (argc=<optimized out>, argv=<optimized out>) at mdadm.c:1629

The direct cause is fd2devnm returning NULL, so add a check.

Signed-off-by: Li Xiao Keng <lixiaokeng@huawei.com>
Signed-off-by: Wu Guang Hao <wuguanghao3@huawei.com>
---
V1->V2: When fd2devnm return NULL, super_by_fd return NULL but not an
incomplete 'st' entry. At the same time, add a check in map_by_devnm
to avoid coredump.

V2->V3: Fix style issues.
V3->V4: Change strcpy() to strncpy().
V4->V5: Move changelog to the location after '---'

 mapfile.c | 4 ++++
 util.c    | 7 ++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/mapfile.c b/mapfile.c
index 8d7acb3..f72fe0d 100644
--- a/mapfile.c
+++ b/mapfile.c
@@ -292,6 +292,10 @@ struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
 struct map_ent *map_by_devnm(struct map_ent **map, char *devnm)
 {
 	struct map_ent *mp;
+
+	if (!devnm)
+		return NULL;
+
 	if (!*map)
 		map_read(map);

diff --git a/util.c b/util.c
index 64dd409..3a84ee3 100644
--- a/util.c
+++ b/util.c
@@ -1241,6 +1241,11 @@ struct supertype *super_by_fd(int fd, char **subarrayp)
 	int i;
 	char *subarray = NULL;
 	char container[32] = "";
+	char *devnm = NULL;
+
+	devnm = fd2devnm(fd);
+	if (!devnm)
+		return NULL;

 	sra = sysfs_read(fd, NULL, GET_VERSION);

@@ -1286,7 +1291,7 @@ struct supertype *super_by_fd(int fd, char **subarrayp)
 		if (subarrayp)
 			*subarrayp = subarray;
 		strcpy(st->container_devnm, container);
-		strcpy(st->devnm, fd2devnm(fd));
+		strncpy(st->devnm, devnm, MD_NAME_MAX - 1);
 	} else
 		free(subarray);

-- 
1.8.3.1

Re: [PATCH V5] Fix NULL dereference in super_by_fd

[Coly Li]

> 2023年2月27日 11:12，Li Xiao Keng <lixiaokeng@huawei.com> 写道：
> 
> When we create 100 partitions (major is 259 not 254) in a raid device,
> mdadm may coredump:
> 
> Core was generated by `/usr/sbin/mdadm --detail --export /dev/md1p7'.
> Program terminated with signal SIGSEGV, Segmentation fault.
> #0  __strlen_avx2_rtm () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
> 74 VPCMPEQ (%rdi), %ymm0, %ymm1
> (gdb) bt
> #0  __strlen_avx2_rtm () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
> #1  0x00007fbb9a7e4139 in __strcpy_chk (dest=dest@entry=0x55d55d6a13ac "", src=0x0, destlen=destlen@entry=32) at strcpy_chk.c:28
> #2  0x000055d55ba1766d in strcpy (__src=<optimized out>, __dest=0x55d55d6a13ac "") at /usr/include/bits/string_fortified.h:79
> #3  super_by_fd (fd=fd@entry=3, subarrayp=subarrayp@entry=0x7fff44dfcc48) at util.c:1289
> #4  0x000055d55ba273a6 in Detail (dev=0x7fff44dfef0b "/dev/md1p7", c=0x7fff44dfe440) at Detail.c:101
> #5  0x000055d55ba0de61 in misc_list (c=<optimized out>, ss=<optimized out>, dump_directory=<optimized out>, ident=<optimized out>, devlist=<optimized out>) at mdadm.c:1959
> #6  main (argc=<optimized out>, argv=<optimized out>) at mdadm.c:1629
> 
> The direct cause is fd2devnm returning NULL, so add a check.
> 
> Signed-off-by: Li Xiao Keng <lixiaokeng@huawei.com>
> Signed-off-by: Wu Guang Hao <wuguanghao3@huawei.com>


Acked-by: Coly Li <colyli@suse.de <mailto:colyli@suse.de>>

Thanks.

Coly Li


> ---
> V1->V2: When fd2devnm return NULL, super_by_fd return NULL but not an
> incomplete 'st' entry. At the same time, add a check in map_by_devnm
> to avoid coredump.
> 
> V2->V3: Fix style issues.
> V3->V4: Change strcpy() to strncpy().
> V4->V5: Move changelog to the location after '---'
> 
> mapfile.c | 4 ++++
> util.c    | 7 ++++++-
> 2 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/mapfile.c b/mapfile.c
> index 8d7acb3..f72fe0d 100644
> --- a/mapfile.c
> +++ b/mapfile.c
> @@ -292,6 +292,10 @@ struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
> struct map_ent *map_by_devnm(struct map_ent **map, char *devnm)
> {
> struct map_ent *mp;
> +
> + if (!devnm)
> + return NULL;
> +
> if (!*map)
> map_read(map);
> 
> diff --git a/util.c b/util.c
> index 64dd409..3a84ee3 100644
> --- a/util.c
> +++ b/util.c
> @@ -1241,6 +1241,11 @@ struct supertype *super_by_fd(int fd, char **subarrayp)
> int i;
> char *subarray = NULL;
> char container[32] = "";
> + char *devnm = NULL;
> +
> + devnm = fd2devnm(fd);
> + if (!devnm)
> + return NULL;
> 
> sra = sysfs_read(fd, NULL, GET_VERSION);
> 
> @@ -1286,7 +1291,7 @@ struct supertype *super_by_fd(int fd, char **subarrayp)
> if (subarrayp)
> *subarrayp = subarray;
> strcpy(st->container_devnm, container);
> - strcpy(st->devnm, fd2devnm(fd));
> + strncpy(st->devnm, devnm, MD_NAME_MAX - 1);
> } else
> free(subarray);
> 
> -- 
> 1.8.3.1

Re: [PATCH V5] Fix NULL dereference in super_by_fd

[Coly Li]

On Mon, Feb 27, 2023 at 11:12:07AM +0800, Li Xiao Keng wrote:
> When we create 100 partitions (major is 259 not 254) in a raid device,
> mdadm may coredump:
> 
> Core was generated by `/usr/sbin/mdadm --detail --export /dev/md1p7'.
> Program terminated with signal SIGSEGV, Segmentation fault.
> #0  __strlen_avx2_rtm () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
> 74		VPCMPEQ	(%rdi), %ymm0, %ymm1
> (gdb) bt
> #0  __strlen_avx2_rtm () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
> #1  0x00007fbb9a7e4139 in __strcpy_chk (dest=dest@entry=0x55d55d6a13ac "", src=0x0, destlen=destlen@entry=32) at strcpy_chk.c:28
> #2  0x000055d55ba1766d in strcpy (__src=<optimized out>, __dest=0x55d55d6a13ac "") at /usr/include/bits/string_fortified.h:79
> #3  super_by_fd (fd=fd@entry=3, subarrayp=subarrayp@entry=0x7fff44dfcc48) at util.c:1289
> #4  0x000055d55ba273a6 in Detail (dev=0x7fff44dfef0b "/dev/md1p7", c=0x7fff44dfe440) at Detail.c:101
> #5  0x000055d55ba0de61 in misc_list (c=<optimized out>, ss=<optimized out>, dump_directory=<optimized out>, ident=<optimized out>, devlist=<optimized out>) at mdadm.c:1959
> #6  main (argc=<optimized out>, argv=<optimized out>) at mdadm.c:1629
> 
> The direct cause is fd2devnm returning NULL, so add a check.
> 
> Signed-off-by: Li Xiao Keng <lixiaokeng@huawei.com>
> Signed-off-by: Wu Guang Hao <wuguanghao3@huawei.com>

Acked-by: Coly Li <colyli@suse.de>


Please forget the previous email, MacOS Mail client "intelligently" extends my email address which is not called for.

Thanks.

Coly Li


> ---
> V1->V2: When fd2devnm return NULL, super_by_fd return NULL but not an
> incomplete 'st' entry. At the same time, add a check in map_by_devnm
> to avoid coredump.
> 
> V2->V3: Fix style issues.
> V3->V4: Change strcpy() to strncpy().
> V4->V5: Move changelog to the location after '---'
> 
>  mapfile.c | 4 ++++
>  util.c    | 7 ++++++-
>  2 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/mapfile.c b/mapfile.c
> index 8d7acb3..f72fe0d 100644
> --- a/mapfile.c
> +++ b/mapfile.c
> @@ -292,6 +292,10 @@ struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
>  struct map_ent *map_by_devnm(struct map_ent **map, char *devnm)
>  {
>  	struct map_ent *mp;
> +
> +	if (!devnm)
> +		return NULL;
> +
>  	if (!*map)
>  		map_read(map);
> 
> diff --git a/util.c b/util.c
> index 64dd409..3a84ee3 100644
> --- a/util.c
> +++ b/util.c
> @@ -1241,6 +1241,11 @@ struct supertype *super_by_fd(int fd, char **subarrayp)
>  	int i;
>  	char *subarray = NULL;
>  	char container[32] = "";
> +	char *devnm = NULL;
> +
> +	devnm = fd2devnm(fd);
> +	if (!devnm)
> +		return NULL;
> 
>  	sra = sysfs_read(fd, NULL, GET_VERSION);
> 
> @@ -1286,7 +1291,7 @@ struct supertype *super_by_fd(int fd, char **subarrayp)
>  		if (subarrayp)
>  			*subarrayp = subarray;
>  		strcpy(st->container_devnm, container);
> -		strcpy(st->devnm, fd2devnm(fd));
> +		strncpy(st->devnm, devnm, MD_NAME_MAX - 1);
>  	} else
>  		free(subarray);
> 
> -- 
> 1.8.3.1

-- 
Coly Li

Re: [PATCH V5] Fix NULL dereference in super_by_fd

[Jes Sorensen]

On 2/26/23 22:12, Li Xiao Keng wrote:
> When we create 100 partitions (major is 259 not 254) in a raid device,
> mdadm may coredump:
> 
> Core was generated by `/usr/sbin/mdadm --detail --export /dev/md1p7'.
> Program terminated with signal SIGSEGV, Segmentation fault.
> #0  __strlen_avx2_rtm () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
> 74		VPCMPEQ	(%rdi), %ymm0, %ymm1
> (gdb) bt
> #0  __strlen_avx2_rtm () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
> #1  0x00007fbb9a7e4139 in __strcpy_chk (dest=dest@entry=0x55d55d6a13ac "", src=0x0, destlen=destlen@entry=32) at strcpy_chk.c:28
> #2  0x000055d55ba1766d in strcpy (__src=<optimized out>, __dest=0x55d55d6a13ac "") at /usr/include/bits/string_fortified.h:79
> #3  super_by_fd (fd=fd@entry=3, subarrayp=subarrayp@entry=0x7fff44dfcc48) at util.c:1289
> #4  0x000055d55ba273a6 in Detail (dev=0x7fff44dfef0b "/dev/md1p7", c=0x7fff44dfe440) at Detail.c:101
> #5  0x000055d55ba0de61 in misc_list (c=<optimized out>, ss=<optimized out>, dump_directory=<optimized out>, ident=<optimized out>, devlist=<optimized out>) at mdadm.c:1959
> #6  main (argc=<optimized out>, argv=<optimized out>) at mdadm.c:1629
> 
> The direct cause is fd2devnm returning NULL, so add a check.
> 
> Signed-off-by: Li Xiao Keng <lixiaokeng@huawei.com>
> Signed-off-by: Wu Guang Hao <wuguanghao3@huawei.com>
> ---
> V1->V2: When fd2devnm return NULL, super_by_fd return NULL but not an
> incomplete 'st' entry. At the same time, add a check in map_by_devnm
> to avoid coredump.
> 
> V2->V3: Fix style issues.
> V3->V4: Change strcpy() to strncpy().
> V4->V5: Move changelog to the location after '---'
> 
>  mapfile.c | 4 ++++
>  util.c    | 7 ++++++-
>  2 files changed, 10 insertions(+), 1 deletion(-)
>

Applied!

Thanks,
Jes