| Message ID | 20230701171134.239409-1-amir73il@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: fix invalid-free in init_file() | expand |
On Sat, 01 Jul 2023 20:11:34 +0300, Amir Goldstein wrote: > The use of file_free_rcu() in init_file() to free the struct that was > allocated by the caller was hacky and we got what we desreved. > > Let init_file() and its callers take care of cleaning up each after > their own allocated resources on error. > > > [...] Thanks for the fix! I'll send a pr shortly. --- Applied to the vfs.fixes branch of the vfs/vfs.git tree. Patches in the vfs.fixes branch should appear in linux-next soon. Please report any outstanding bugs that were missed during review in a new review to the original patch series allowing us to drop it. It's encouraged to provide Acked-bys and Reviewed-bys even though the patch has now been applied. If possible patch trailers will be updated. Note that commit hashes shown below are subject to change due to rebase, trailer updates or similar. If in doubt, please check the listed branch. tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git branch: vfs.fixes [1/1] fs: move cleanup from init_file() into its callers https://git.kernel.org/vfs/vfs/c/dff745c1221a
diff --git a/fs/file_table.c b/fs/file_table.c index e06c68e2d757..fc7d677ff5ad 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -160,7 +160,7 @@ static int init_file(struct file *f, int flags, const struct cred *cred) f->f_cred = get_cred(cred); error = security_file_alloc(f); if (unlikely(error)) { - file_free_rcu(&f->f_rcuhead); + put_cred(f->f_cred); return error; } @@ -208,8 +208,10 @@ struct file *alloc_empty_file(int flags, const struct cred *cred) return ERR_PTR(-ENOMEM); error = init_file(f, flags, cred); - if (unlikely(error)) + if (unlikely(error)) { + kmem_cache_free(filp_cachep, f); return ERR_PTR(error); + } percpu_counter_inc(&nr_files); @@ -240,8 +242,10 @@ struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred) return ERR_PTR(-ENOMEM); error = init_file(f, flags, cred); - if (unlikely(error)) + if (unlikely(error)) { + kmem_cache_free(filp_cachep, f); return ERR_PTR(error); + } f->f_mode |= FMODE_NOACCOUNT; @@ -265,8 +269,10 @@ struct file *alloc_empty_backing_file(int flags, const struct cred *cred) return ERR_PTR(-ENOMEM); error = init_file(&ff->file, flags, cred); - if (unlikely(error)) + if (unlikely(error)) { + kfree(ff); return ERR_PTR(error); + } ff->file.f_mode |= FMODE_BACKING | FMODE_NOACCOUNT; return &ff->file;
The use of file_free_rcu() in init_file() to free the struct that was allocated by the caller was hacky and we got what we desreved. Let init_file() and its callers take care of cleaning up each after their own allocated resources on error. Reported-by: syzbot+ada42aab05cf51b00e98@syzkaller.appspotmail.com Fixes: 62d53c4a1dfe ("fs: use backing_file container for internal files with "fake" f_path") Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- fs/file_table.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)