This is a note to let you know that I've just added the patch titled
m68k: Fix kernel_clone_args.flags in m68k_clone()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
m68k-fix-kernel_clone_args.flags-in-m68k_clone.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 82dcd67a46decce137ddd4dbcf5892c747f25030
Author: Finn Thain <fthain@xxxxxxxxxxxxxx>
Date: Sun Aug 11 10:12:29 2024 +1000
m68k: Fix kernel_clone_args.flags in m68k_clone()
[ Upstream commit 09b3d870faa7bc3e96c0978ab3cf4e96e4b15571 ]
Stan Johnson recently reported a failure from the 'dump' command:
DUMP: Date of this level 0 dump: Fri Aug 9 23:37:15 2024
DUMP: Dumping /dev/sda (an unlisted file system) to /dev/null
DUMP: Label: none
DUMP: Writing 10 Kilobyte records
DUMP: mapping (Pass I) [regular files]
DUMP: mapping (Pass II) [directories]
DUMP: estimated 3595695 blocks.
DUMP: Context save fork fails in parent 671
The dump program uses the clone syscall with the CLONE_IO flag, that is,
flags == 0x80000000. When that value is promoted from long int to u64 by
m68k_clone(), it undergoes sign-extension. The new value includes
CLONE_INTO_CGROUP so the validation in cgroup_css_set_fork() fails and
the syscall returns -EBADF. Avoid sign-extension by casting to u32.
Reported-by: Stan Johnson <userm57@xxxxxxxxx>
Closes: https://lists.debian.org/debian-68k/2024/08/msg00000.html
Fixes: 6aabc1facdb2 ("m68k: Implement copy_thread_tls()")
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/3463f1e5d4e95468dc9f3368f2b78ffa7b72199b.1723335149.git.fthain@xxxxxxxxxxxxxx
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index e06ce147c0b7f..fb87219fc3b46 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -116,7 +116,7 @@ asmlinkage int m68k_clone(struct pt_regs *regs)
{
/* regs will be equal to current_pt_regs() */
struct kernel_clone_args args = {
- .flags = regs->d1 & ~CSIGNAL,
+ .flags = (u32)(regs->d1) & ~CSIGNAL,
.pidfd = (int __user *)regs->d3,
.child_tid = (int __user *)regs->d4,
.parent_tid = (int __user *)regs->d3,
