Found a bug with the source / dest length
updated to have size limit as the size of dest not size or source.
Signed-off-by: Derek Robson <[email protected]>
---
arch/x86/ia32/ia32_aout.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
index f65b78d32f5e..1e7f71723ee0 100644
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -157,7 +157,7 @@ static int aout_core_dump(struct coredump_params *cprm)
fs = get_fs();
set_fs(KERNEL_DS);
has_dumped = 1;
- strncpy(dump.u_comm, current->comm, sizeof(current->comm));
+ strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
dump.u_ar0 = offsetof(struct user32, regs);
dump.signal = cprm->siginfo->si_signo;
dump_thread32(cprm->regs, &dump);
--
2.20.1
On Sat, Feb 02, 2019 at 01:55:12PM +1300, Derek Robson wrote:
> Found a bug with the source / dest length
> updated to have size limit as the size of dest not size or source.
>
> Signed-off-by: Derek Robson <[email protected]>
> ---
> arch/x86/ia32/ia32_aout.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
> index f65b78d32f5e..1e7f71723ee0 100644
> --- a/arch/x86/ia32/ia32_aout.c
> +++ b/arch/x86/ia32/ia32_aout.c
> @@ -157,7 +157,7 @@ static int aout_core_dump(struct coredump_params *cprm)
> fs = get_fs();
> set_fs(KERNEL_DS);
> has_dumped = 1;
> - strncpy(dump.u_comm, current->comm, sizeof(current->comm));
> + strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
Are you sure this is correct?
From looking at this, I think there's something else wrong with this
code though.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
Commit-ID: 10970e1b4be9c74fce8ab6e3c34a7d718f063f2c
Gitweb: https://git.kernel.org/tip/10970e1b4be9c74fce8ab6e3c34a7d718f063f2c
Author: Borislav Petkov <[email protected]>
AuthorDate: Tue, 12 Feb 2019 14:28:03 +0100
Committer: Borislav Petkov <[email protected]>
CommitDate: Wed, 13 Feb 2019 12:10:51 +0100
x86/a.out: Clear the dump structure initially
dump_thread32() in aout_core_dump() does not clear the user32 structure
allocated on the stack as the first thing on function entry.
As a result, the dump.u_comm, dump.u_ar0 and dump.signal which get
assigned before the clearing, get overwritten.
Rename that function to fill_dump() to make it clear what it does and
call it first thing.
This was caught while staring at a patch by Derek Robson
<[email protected]>.
Signed-off-by: Borislav Petkov <[email protected]>
Cc: Derek Robson <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Michael Matz <[email protected]>
Cc: [email protected]
Cc: <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
arch/x86/ia32/ia32_aout.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
index f65b78d32f5e..7dbbe9ffda17 100644
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -51,7 +51,7 @@ static unsigned long get_dr(int n)
/*
* fill in the user structure for a core dump..
*/
-static void dump_thread32(struct pt_regs *regs, struct user32 *dump)
+static void fill_dump(struct pt_regs *regs, struct user32 *dump)
{
u32 fs, gs;
memset(dump, 0, sizeof(*dump));
@@ -157,10 +157,12 @@ static int aout_core_dump(struct coredump_params *cprm)
fs = get_fs();
set_fs(KERNEL_DS);
has_dumped = 1;
+
+ fill_dump(cprm->regs, &dump);
+
strncpy(dump.u_comm, current->comm, sizeof(current->comm));
dump.u_ar0 = offsetof(struct user32, regs);
dump.signal = cprm->siginfo->si_signo;
- dump_thread32(cprm->regs, &dump);
/*
* If the size of the dump file exceeds the rlimit, then see