From e240c1b3635e3fc7d3ba46c6fe12a0d8efb2941a Mon Sep 17 00:00:00 2001 From: Su Yue Date: Mon, 8 Jan 2024 23:11:08 +0800 Subject: bcachefs: fix memleak in bch2_split_devs The pointer dev_name can be modified by strseq(), then causes the memleak: unreferenced object 0xffff9d08a2916c80 (size 32): comm "mount.bcachefs", pid 9090, jiffies 4295856224 (age 17.564s) hex dump (first 32 bytes): 2f 64 65 76 2f 6d 61 70 70 65 72 2f 74 65 73 74 /dev/mapper/test 2d 30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -0.............. backtrace: [<00000000c5d3be7d>] __kmem_cache_alloc_node+0x1f3/0x2c0 [<0000000052215d26>] __kmalloc_node_track_caller+0x51/0x150 [<0000000069fea956>] kstrdup+0x32/0x60 [<000000000877fcf1>] bch2_split_devs+0x3f/0x150 [bcachefs] [<000000007ee93204>] bch2_mount+0xcb/0x640 [bcachefs] [<000000002dd1e04b>] legacy_get_tree+0x30/0x60 [<000000006afc31d3>] vfs_get_tree+0x28/0xf0 [<000000007b0c538e>] path_mount+0x475/0xb60 [<0000000092de5882>] __x64_sys_mount+0x105/0x140 [<0000000054fc05d8>] do_syscall_64+0x42/0xf0 [<00000000df584910>] entry_SYSCALL_64_after_hwframe+0x6e/0x76 Fix it by copy pointer dev_name at beginning and free the copied pointer at end. Signed-off-by: Su Yue Reviewed-by: Brian Foster Signed-off-by: Kent Overstreet --- fs/bcachefs/util.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'fs') diff --git a/fs/bcachefs/util.c b/fs/bcachefs/util.c index c2ef7cddaa4f..f927c8a19e24 100644 --- a/fs/bcachefs/util.c +++ b/fs/bcachefs/util.c @@ -1186,7 +1186,9 @@ int bch2_split_devs(const char *_dev_name, darray_str *ret) { darray_init(ret); - char *dev_name = kstrdup(_dev_name, GFP_KERNEL), *s = dev_name; + char *dev_name, *s, *orig; + + dev_name = orig = kstrdup(_dev_name, GFP_KERNEL); if (!dev_name) return -ENOMEM; @@ -1201,10 +1203,10 @@ int bch2_split_devs(const char *_dev_name, darray_str *ret) } } - kfree(dev_name); + kfree(orig); return 0; err: bch2_darray_str_exit(ret); - kfree(dev_name); + kfree(orig); return -ENOMEM; } -- cgit v1.2.3