CVE-2023-53234 — linux / linux_kernel
Missing Release of Memory after Effective LifetimeIn the Linux kernel, the following vulnerability has been resolved:
watchdog: Fix kmemleak in watchdog_cdev_register
kmemleak reports memory leaks in watchdog_dev_register, as follows: unreferenced object 0xffff888116233000 (size 2048): comm ""modprobe"", pid 28147, jiffies 4353426116 (age 61.741s) hex dump (first 32 bytes): 80 fa b9 05 81 88 ff ff 08 30 23 16 81 88 ff ff .........0#..... 08 30 23 16 81 88 ff ff 00 00 00 00 00 00 00 00 .0#............. backtrace: [<000000007f001ffd>] __kmem_cache_alloc_node+0x157/0x220 [<000000006a389304>] kmalloc_trace+0x21/0x110 [<000000008d640eea>] watchdog_dev_register+0x4e/0x780 [watchdog] [<0000000053c9f248>] __watchdog_register_device+0x4f0/0x680 [watchdog] [<00000000b2979824>] watchdog_register_device+0xd2/0x110 [watchdog] [<000000001f730178>] 0xffffffffc10880ae [<000000007a1a8bcc>] do_one_initcall+0xcb/0x4d0 [<00000000b98be325>] do_init_module+0x1ca/0x5f0 [<0000000046d08e7c>] load_module+0x6133/0x70f0 ...
unreferenced object 0xffff888105b9fa80 (size 16): comm ""modprobe"", pid 28147, jiffies 4353426116 (age 61.741s) hex dump (first 16 bytes): 77 61 74 63 68 64 6f 67 31 00 b9 05 81 88 ff ff watchdog1....... backtrace: [<000000007f001ffd>] __kmem_cache_alloc_node+0x157/0x220 [<00000000486ab89b>] __kmalloc_node_track_caller+0x44/0x1b0 [<000000005a39aab0>] kvasprintf+0xb5/0x140 [<0000000024806f85>] kvasprintf_const+0x55/0x180 [<000000009276cb7f>] kobject_set_name_vargs+0x56/0x150 [<00000000a92e820b>] dev_set_name+0xab/0xe0 [<00000000cec812c6>] watchdog_dev_register+0x285/0x780 [watchdog] [<0000000053c9f248>] __watchdog_register_device+0x4f0/0x680 [watchdog] [<00000000b2979824>] watchdog_register_device+0xd2/0x110 [watchdog] [<000000001f730178>] 0xffffffffc10880ae [<000000007a1a8bcc>] do_one_initcall+0xcb/0x4d0 [<00000000b98be325>] do_init_module+0x1ca/0x5f0 [<0000000046d08e7c>] load_module+0x6133/0x70f0 ...
The reason is that put_device is not be called if cdev_device_add fails and wdd->id != 0.
watchdog_cdev_register wd_data = kzalloc [1] err = dev_set_name [2] .. err = cdev_device_add if (err) { if (wdd->id == 0) { // wdd->id != 0 .. } return err; // [1],[2] would be leaked
To fix it, call put_device in all wdd->id cases.
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 4.9.225 | 4.10 |
| linux / linux_kernel | 4.14.182 | 4.14.308 |
| linux / linux_kernel | 4.19.93 | 4.19.276 |
| linux / linux_kernel | 5.4.8 | 5.4.235 |
| linux / linux_kernel | 5.5 | 5.10.173 |
| linux / linux_kernel | 5.11 | 5.15.100 |
| linux / linux_kernel | 5.16 | 6.1.18 |
| linux / linux_kernel | 6.2 | 6.2.5 |
- https://git.kernel.org/stable/c/13721a2ac66b246f5802ba1b75ad8637e53eeecc
- https://git.kernel.org/stable/c/23cc41c3f19c4d858c3708f1c0a06e94958e6c3b
- https://git.kernel.org/stable/c/50808d034e199fe3ff7a9d2068a4eebeb6b4098a
- https://git.kernel.org/stable/c/59e391b3fc507a15b7e8e9d9f4de87cae177c366
- https://git.kernel.org/stable/c/8c1655600f4f2839fb844fe8c70b2b65fadc7a56
- https://git.kernel.org/stable/c/ac099d94e0480c937aa9172ab64074981ca1a4d3
- https://git.kernel.org/stable/c/bf26b0e430ce34261f45959989edaf680b64d538
- https://git.kernel.org/stable/c/c5a21a5501508ae3afa2fe6d5a3e74a37fa48df3
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