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) <rostedt@goodmis.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Hui Su 2020-11-25 00:52:05 +08:00 committed by Jan Kara
parent 127c501a03
commit fdeb17c70c

View File

@ -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;