From fdeb17c70c9ecae655378761accf5a26a55a33cf Mon Sep 17 00:00:00 2001 From: Hui Su Date: Wed, 25 Nov 2020 00:52:05 +0800 Subject: [PATCH] trace: fix potenial dangerous pointer The bdi_dev_name() returns a char [64], and the __entry->name is a char [32]. It maybe dangerous to TP_printk("%s", __entry->name) after the strncpy(). CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201124165205.GA23937@rlk Acked-by: Steven Rostedt (VMware) Acked-by: Tejun Heo Signed-off-by: Hui Su Signed-off-by: Jan Kara --- include/trace/events/writeback.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index e7cbccc7c14c..57d795365987 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -190,7 +190,7 @@ TRACE_EVENT(inode_foreign_history, ), TP_fast_assign( - strncpy(__entry->name, bdi_dev_name(inode_to_bdi(inode)), 32); + strscpy_pad(__entry->name, bdi_dev_name(inode_to_bdi(inode)), 32); __entry->ino = inode->i_ino; __entry->cgroup_ino = __trace_wbc_assign_cgroup(wbc); __entry->history = history; @@ -219,7 +219,7 @@ TRACE_EVENT(inode_switch_wbs, ), TP_fast_assign( - strncpy(__entry->name, bdi_dev_name(old_wb->bdi), 32); + strscpy_pad(__entry->name, bdi_dev_name(old_wb->bdi), 32); __entry->ino = inode->i_ino; __entry->old_cgroup_ino = __trace_wb_assign_cgroup(old_wb); __entry->new_cgroup_ino = __trace_wb_assign_cgroup(new_wb); @@ -252,7 +252,7 @@ TRACE_EVENT(track_foreign_dirty, struct address_space *mapping = page_mapping(page); struct inode *inode = mapping ? mapping->host : NULL; - strncpy(__entry->name, bdi_dev_name(wb->bdi), 32); + strscpy_pad(__entry->name, bdi_dev_name(wb->bdi), 32); __entry->bdi_id = wb->bdi->id; __entry->ino = inode ? inode->i_ino : 0; __entry->memcg_id = wb->memcg_css->id; @@ -285,7 +285,7 @@ TRACE_EVENT(flush_foreign, ), TP_fast_assign( - strncpy(__entry->name, bdi_dev_name(wb->bdi), 32); + strscpy_pad(__entry->name, bdi_dev_name(wb->bdi), 32); __entry->cgroup_ino = __trace_wb_assign_cgroup(wb); __entry->frn_bdi_id = frn_bdi_id; __entry->frn_memcg_id = frn_memcg_id;