6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Frank Sorenson [ Upstream commit c2f2e83e3bbc5483730fd4ee903182761f1ae50f ] In cifs_close_deferred_file(), cifs_close_all_deferred_files(), and cifs_close_deferred_file_under_dentry(), when a pending deferred close is cancelled via cancel_delayed_work(), the subsequent kmalloc_obj() to add the file to the local processing list may fail under memory pressure. The loop breaks immediately, but the cancelled work is no longer pending (it would have called _cifsFileInfo_put()), and the cfile is never added to file_head for processing. The cifsFileInfo reference and the open server handle both leak. Fix by saving the cfile that failed allocation in a local variable, breaking as before, and calling _cifsFileInfo_put() on it after releasing the lock. Any files later in the iteration are unaffected since their deferred work is still pending and will fire normally. Fixes: e3fc065682eb ("cifs: Deferred close performance improvements") Signed-off-by: Frank Sorenson Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/smb/client/misc.c | 45 ++++++++++++++++++++++++++++++++++++++------ 1 file changed, 39 insertions(+), 6 deletions(-) diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c index 0703e06aba1ed..cbbd7ac83c5f7 100644 --- a/fs/smb/client/misc.c +++ b/fs/smb/client/misc.c @@ -776,7 +776,7 @@ cifs_del_deferred_close(struct cifsFileInfo *cfile) void cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) { - struct cifsFileInfo *cfile = NULL; + struct cifsFileInfo *cfile = NULL, *failed_cfile = NULL; struct file_list *tmp_list, *tmp_next_list; LIST_HEAD(file_head); @@ -793,8 +793,10 @@ cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) tmp_list = kmalloc_obj(struct file_list, GFP_ATOMIC); - if (tmp_list == NULL) + if (tmp_list == NULL) { + failed_cfile = cfile; break; + } tmp_list->cfile = cfile; list_add_tail(&tmp_list->list, &file_head); } @@ -802,6 +804,15 @@ cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) } spin_unlock(&cifs_inode->open_file_lock); + if (failed_cfile) { + if (OPEN_FMODE(failed_cfile->f_flags) & FMODE_WRITE) { + /* Pairs with smp_load_acquire() in is_size_safe_to_change(). */ + smp_store_release(&CIFS_I(d_inode(failed_cfile->dentry))->time_last_write, + jiffies); + } + _cifsFileInfo_put(failed_cfile, false, false); + } + list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { struct cifsFileInfo *cfile = tmp_list->cfile; @@ -819,7 +830,7 @@ cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) void cifs_close_all_deferred_files(struct cifs_tcon *tcon) { - struct cifsFileInfo *cfile; + struct cifsFileInfo *cfile, *failed_cfile = NULL; struct file_list *tmp_list, *tmp_next_list; LIST_HEAD(file_head); @@ -833,8 +844,10 @@ cifs_close_all_deferred_files(struct cifs_tcon *tcon) tmp_list = kmalloc_obj(struct file_list, GFP_ATOMIC); - if (tmp_list == NULL) + if (tmp_list == NULL) { + failed_cfile = cfile; break; + } tmp_list->cfile = cfile; list_add_tail(&tmp_list->list, &file_head); } @@ -842,6 +855,15 @@ cifs_close_all_deferred_files(struct cifs_tcon *tcon) } spin_unlock(&tcon->open_file_lock); + if (failed_cfile) { + if (OPEN_FMODE(failed_cfile->f_flags) & FMODE_WRITE) { + /* Pairs with smp_load_acquire() in is_size_safe_to_change(). */ + smp_store_release(&CIFS_I(d_inode(failed_cfile->dentry))->time_last_write, + jiffies); + } + _cifsFileInfo_put(failed_cfile, true, false); + } + list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { struct cifsFileInfo *cfile = tmp_list->cfile; @@ -897,7 +919,7 @@ void cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, struct dentry *dentry) { struct file_list *tmp_list, *tmp_next_list; - struct cifsFileInfo *cfile; + struct cifsFileInfo *cfile, *failed_cfile = NULL; LIST_HEAD(file_head); spin_lock(&tcon->open_file_lock); @@ -910,14 +932,25 @@ void cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); tmp_list = kmalloc_obj(struct file_list, GFP_ATOMIC); - if (tmp_list == NULL) + if (tmp_list == NULL) { + failed_cfile = cfile; break; + } tmp_list->cfile = cfile; list_add_tail(&tmp_list->list, &file_head); } } spin_unlock(&tcon->open_file_lock); + if (failed_cfile) { + if (OPEN_FMODE(failed_cfile->f_flags) & FMODE_WRITE) { + /* Pairs with smp_load_acquire() in is_size_safe_to_change(). */ + smp_store_release(&CIFS_I(d_inode(failed_cfile->dentry))->time_last_write, + jiffies); + } + _cifsFileInfo_put(failed_cfile, true, false); + } + list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { struct cifsFileInfo *cfile = tmp_list->cfile; -- 2.53.0