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| author | Christian Brauner <brauner@kernel.org> | 2026-06-01 15:56:44 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-06-29 10:44:08 +0200 |
| commit | fea1107ff33cd3412652307b9ff911055b197364 (patch) | |
| tree | 60617b6a68b8bfb96ffbb4a7ff67491686485d51 | |
| parent | f565f3b06465725cae35f873d053cab14297eb73 (diff) | |
| download | linux-stable-fea1107ff33cd3412652307b9ff911055b197364.tar.gz linux-stable-fea1107ff33cd3412652307b9ff911055b197364.zip | |
coredump: use scoped_with_init_fs() for coredump path resolution
Use scoped_with_init_fs() to temporarily override current->fs for
the filp_open() call so the coredump path lookup happens in init's
filesystem context. This replaces the init_root() + file_open_root()
pattern with the simpler scoped override.
coredump_file() ← do_coredump() ← vfs_coredump() ← get_signal() — runs
as the crashing userspace process
Uses init's root to prevent a chrooted/user-namespaced process from
controlling where suid coredumps land. Not a kthread, but intentionally
needs init's fs for security.
Link: https://patch.msgid.link/20260601-work-kthread-nullfs-v4-11-77ee053060e0@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
| -rw-r--r-- | fs/coredump.c | 11 |
1 files changed, 3 insertions, 8 deletions
diff --git a/fs/coredump.c b/fs/coredump.c index e68a76ff92a3..ac3cd74808c6 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -921,15 +921,10 @@ static bool coredump_file(struct core_name *cn, struct coredump_params *cprm, * with a fully qualified path" rule is to control where * coredumps may be placed using root privileges, * current->fs->root must not be used. Instead, use the - * root directory of init_task. + * root directory of PID 1. */ - struct path root; - - task_lock(&init_task); - get_fs_root(init_task.fs, &root); - task_unlock(&init_task); - file = file_open_root(&root, cn->corename, open_flags, 0600); - path_put(&root); + scoped_with_init_fs() + file = filp_open(cn->corename, open_flags, 0600); } else { file = filp_open(cn->corename, open_flags, 0600); } |