6.5-stable review patch. If anyone has any objections, please let me know.
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From: Will Shiu Will.Shiu@mediatek.com
[ Upstream commit 74f6f5912693ce454384eaeec48705646a21c74f ]
As following backtrace, the struct file_lock request , in posix_lock_inode is free before ftrace function using. Replace the ftrace function ahead free flow could fix the use-after-free issue.
[name:report&]=============================================== BUG:KASAN: use-after-free in trace_event_raw_event_filelock_lock+0x80/0x12c [name:report&]Read at addr f6ffff8025622620 by task NativeThread/16753 [name:report_hw_tags&]Pointer tag: [f6], memory tag: [fe] [name:report&] BT: Hardware name: MT6897 (DT) Call trace: dump_backtrace+0xf8/0x148 show_stack+0x18/0x24 dump_stack_lvl+0x60/0x7c print_report+0x2c8/0xa08 kasan_report+0xb0/0x120 __do_kernel_fault+0xc8/0x248 do_bad_area+0x30/0xdc do_tag_check_fault+0x1c/0x30 do_mem_abort+0x58/0xbc el1_abort+0x3c/0x5c el1h_64_sync_handler+0x54/0x90 el1h_64_sync+0x68/0x6c trace_event_raw_event_filelock_lock+0x80/0x12c posix_lock_inode+0xd0c/0xd60 do_lock_file_wait+0xb8/0x190 fcntl_setlk+0x2d8/0x440 ... [name:report&] [name:report&]Allocated by task 16752: ... slab_post_alloc_hook+0x74/0x340 kmem_cache_alloc+0x1b0/0x2f0 posix_lock_inode+0xb0/0xd60 ... [name:report&] [name:report&]Freed by task 16752: ... kmem_cache_free+0x274/0x5b0 locks_dispose_list+0x3c/0x148 posix_lock_inode+0xc40/0xd60 do_lock_file_wait+0xb8/0x190 fcntl_setlk+0x2d8/0x440 do_fcntl+0x150/0xc18 ...
Signed-off-by: Will Shiu Will.Shiu@mediatek.com Signed-off-by: Jeff Layton jlayton@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/locks.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/locks.c b/fs/locks.c index df8b26a425248..a552bdb6badc0 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1301,6 +1301,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request, out: spin_unlock(&ctx->flc_lock); percpu_up_read(&file_rwsem); + trace_posix_lock_inode(inode, request, error); /* * Free any unused locks. */ @@ -1309,7 +1310,6 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request, if (new_fl2) locks_free_lock(new_fl2); locks_dispose_list(&dispose); - trace_posix_lock_inode(inode, request, error);
return error; }