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| author | Finn Thain <fthain@linux-m68k.org> | 2024-08-11 10:12:29 +1000 |
|---|---|---|
| committer | Geert Uytterhoeven <geert@linux-m68k.org> | 2024-08-26 10:24:34 +0200 |
| commit | 09b3d870faa7bc3e96c0978ab3cf4e96e4b15571 (patch) | |
| tree | 1476992c45f13e581e6b14741c4a3496f3bbf612 /arch/m68k | |
| parent | 61eb040228ba9a0657937a1e48d6696f66364a55 (diff) | |
m68k: Fix kernel_clone_args.flags in m68k_clone()
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@yahoo.com>
Closes: https://lists.debian.org/debian-68k/2024/08/msg00000.html
Fixes: 6aabc1facdb2 ("m68k: Implement copy_thread_tls()")
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/3463f1e5d4e95468dc9f3368f2b78ffa7b72199b.1723335149.git.fthain@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k')
| -rw-r--r-- | arch/m68k/kernel/process.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c index 2584e94e2134..fda7eac23f87 100644 --- a/arch/m68k/kernel/process.c +++ b/arch/m68k/kernel/process.c @@ -117,7 +117,7 @@ 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, |