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authorVamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>2020-04-22 11:45:06 +0530
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2020-04-22 21:24:00 -0400
commit9da73974eb9c965dd9989befb593b8c8da9e4bdc (patch)
tree80749d8d43b3ebf4bbc03dbe88ee33abecc85f10 /kernel/trace
parentae83d0b416db002fe95601e7f97f64b59514d936 (diff)
tracing: Fix memory leaks in trace_events_hist.c
kmemleak report 1: [<9092c50b>] kmem_cache_alloc_trace+0x138/0x270 [<05a2c9ed>] create_field_var+0xcf/0x180 [<528a2d68>] action_create+0xe2/0xc80 [<63f50b61>] event_hist_trigger_func+0x15b5/0x1920 [<28ea5d3d>] trigger_process_regex+0x7b/0xc0 [<3138e86f>] event_trigger_write+0x4d/0xb0 [<ffd66c19>] __vfs_write+0x30/0x200 [<4f424a0d>] vfs_write+0x96/0x1b0 [<da59a290>] ksys_write+0x53/0xc0 [<3717101a>] __ia32_sys_write+0x15/0x20 [<c5f23497>] do_fast_syscall_32+0x70/0x250 [<46e2629c>] entry_SYSENTER_32+0xaf/0x102 This is because save_vars[] of struct hist_trigger_data are not destroyed kmemleak report 2: [<9092c50b>] kmem_cache_alloc_trace+0x138/0x270 [<6e5e97c5>] create_var+0x3c/0x110 [<de82f1b9>] create_field_var+0xaf/0x180 [<528a2d68>] action_create+0xe2/0xc80 [<63f50b61>] event_hist_trigger_func+0x15b5/0x1920 [<28ea5d3d>] trigger_process_regex+0x7b/0xc0 [<3138e86f>] event_trigger_write+0x4d/0xb0 [<ffd66c19>] __vfs_write+0x30/0x200 [<4f424a0d>] vfs_write+0x96/0x1b0 [<da59a290>] ksys_write+0x53/0xc0 [<3717101a>] __ia32_sys_write+0x15/0x20 [<c5f23497>] do_fast_syscall_32+0x70/0x250 [<46e2629c>] entry_SYSENTER_32+0xaf/0x102 struct hist_field allocated through create_var() do not initialize "ref" field to 1. The code in __destroy_hist_field() does not destroy object if "ref" is initialized to zero, the condition if (--hist_field->ref > 1) always passes since unsigned int wraps. kmemleak report 3: [<f8666fcc>] __kmalloc_track_caller+0x139/0x2b0 [<bb7f80a5>] kstrdup+0x27/0x50 [<39d70006>] init_var_ref+0x58/0xd0 [<8ca76370>] create_var_ref+0x89/0xe0 [<f045fc39>] action_create+0x38f/0xc80 [<7c146821>] event_hist_trigger_func+0x15b5/0x1920 [<07de3f61>] trigger_process_regex+0x7b/0xc0 [<e87daf8f>] event_trigger_write+0x4d/0xb0 [<19bf1512>] __vfs_write+0x30/0x200 [<64ce4d27>] vfs_write+0x96/0x1b0 [<a6f34170>] ksys_write+0x53/0xc0 [<7d4230cd>] __ia32_sys_write+0x15/0x20 [<8eadca00>] do_fast_syscall_32+0x70/0x250 [<235cf985>] entry_SYSENTER_32+0xaf/0x102 hist_fields (system & event_name) are not freed Link: http://lkml.kernel.org/r/20200422061503.GA5151@cosmos Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace_events_hist.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 5f6834a2bf41..fcab11cc6833 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3320,6 +3320,9 @@ static void __destroy_hist_field(struct hist_field *hist_field)
kfree(hist_field->name);
kfree(hist_field->type);
+ kfree(hist_field->system);
+ kfree(hist_field->event_name);
+
kfree(hist_field);
}
@@ -4382,6 +4385,7 @@ static struct hist_field *create_var(struct hist_trigger_data *hist_data,
goto out;
}
+ var->ref = 1;
var->flags = HIST_FIELD_FL_VAR;
var->var.idx = idx;
var->var.hist_data = var->hist_data = hist_data;
@@ -5011,6 +5015,9 @@ static void destroy_field_vars(struct hist_trigger_data *hist_data)
for (i = 0; i < hist_data->n_field_vars; i++)
destroy_field_var(hist_data->field_vars[i]);
+
+ for (i = 0; i < hist_data->n_save_vars; i++)
+ destroy_field_var(hist_data->save_vars[i]);
}
static void save_field_var(struct hist_trigger_data *hist_data,