| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2021-47238: net: ipv4: fix memory leak in ip_mc_add1_src |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net: ipv4: fix memory leak in ip_mc_add1_src |
| |
| BUG: memory leak |
| unreferenced object 0xffff888101bc4c00 (size 32): |
| comm "syz-executor527", pid 360, jiffies 4294807421 (age 19.329s) |
| hex dump (first 32 bytes): |
| 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ |
| 01 00 00 00 00 00 00 00 ac 14 14 bb 00 00 02 00 ................ |
| backtrace: |
| [<00000000f17c5244>] kmalloc include/linux/slab.h:558 [inline] |
| [<00000000f17c5244>] kzalloc include/linux/slab.h:688 [inline] |
| [<00000000f17c5244>] ip_mc_add1_src net/ipv4/igmp.c:1971 [inline] |
| [<00000000f17c5244>] ip_mc_add_src+0x95f/0xdb0 net/ipv4/igmp.c:2095 |
| [<000000001cb99709>] ip_mc_source+0x84c/0xea0 net/ipv4/igmp.c:2416 |
| [<0000000052cf19ed>] do_ip_setsockopt net/ipv4/ip_sockglue.c:1294 [inline] |
| [<0000000052cf19ed>] ip_setsockopt+0x114b/0x30c0 net/ipv4/ip_sockglue.c:1423 |
| [<00000000477edfbc>] raw_setsockopt+0x13d/0x170 net/ipv4/raw.c:857 |
| [<00000000e75ca9bb>] __sys_setsockopt+0x158/0x270 net/socket.c:2117 |
| [<00000000bdb993a8>] __do_sys_setsockopt net/socket.c:2128 [inline] |
| [<00000000bdb993a8>] __se_sys_setsockopt net/socket.c:2125 [inline] |
| [<00000000bdb993a8>] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2125 |
| [<000000006a1ffdbd>] do_syscall_64+0x40/0x80 arch/x86/entry/common.c:47 |
| [<00000000b11467c4>] entry_SYSCALL_64_after_hwframe+0x44/0xae |
| |
| In commit 24803f38a5c0 ("igmp: do not remove igmp souce list info when set |
| link down"), the ip_mc_clear_src() in ip_mc_destroy_dev() was removed, |
| because it was also called in igmpv3_clear_delrec(). |
| |
| Rough callgraph: |
| |
| inetdev_destroy |
| -> ip_mc_destroy_dev |
| -> igmpv3_clear_delrec |
| -> ip_mc_clear_src |
| -> RCU_INIT_POINTER(dev->ip_ptr, NULL) |
| |
| However, ip_mc_clear_src() called in igmpv3_clear_delrec() doesn't |
| release in_dev->mc_list->sources. And RCU_INIT_POINTER() assigns the |
| NULL to dev->ip_ptr. As a result, in_dev cannot be obtained through |
| inetdev_by_index() and then in_dev->mc_list->sources cannot be released |
| by ip_mc_del1_src() in the sock_close. Rough call sequence goes like: |
| |
| sock_close |
| -> __sock_release |
| -> inet_release |
| -> ip_mc_drop_socket |
| -> inetdev_by_index |
| -> ip_mc_leave_src |
| -> ip_mc_del_src |
| -> ip_mc_del1_src |
| |
| So we still need to call ip_mc_clear_src() in ip_mc_destroy_dev() to free |
| in_dev->mc_list->sources. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47238 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.9 with commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a and fixed in 4.9.274 with commit 0dc13e75507faa17ac9f7562b4ef7bf8fcd78422 |
| Issue introduced in 4.9 with commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a and fixed in 4.14.238 with commit 6cff57eea3347f79f1867cc53e1093b6614138d8 |
| Issue introduced in 4.9 with commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a and fixed in 4.19.196 with commit 1e28018b5c83d5073f74a6fb72eabe8370b2f501 |
| Issue introduced in 4.9 with commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a and fixed in 5.4.128 with commit 3dd2aeac2e9624cff9fa634710837e4f2e352758 |
| Issue introduced in 4.9 with commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a and fixed in 5.10.46 with commit ac31cc837cafb57a271babad8ccffbf733caa076 |
| Issue introduced in 4.9 with commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a and fixed in 5.12.13 with commit 77de6ee73f54a9a89c0afa0bf4c53b239aa9953a |
| Issue introduced in 4.9 with commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a and fixed in 5.13 with commit d8e2973029b8b2ce477b564824431f3385c77083 |
| Issue introduced in 3.2.87 with commit bd1b664a19403ede448d29c87b2f23796bc7a577 |
| Issue introduced in 3.16.42 with commit b38c6e0bd5b5e439ecebdc0df599d573c2f610f8 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2021-47238 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| net/ipv4/igmp.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/0dc13e75507faa17ac9f7562b4ef7bf8fcd78422 |
| https://git.kernel.org/stable/c/6cff57eea3347f79f1867cc53e1093b6614138d8 |
| https://git.kernel.org/stable/c/1e28018b5c83d5073f74a6fb72eabe8370b2f501 |
| https://git.kernel.org/stable/c/3dd2aeac2e9624cff9fa634710837e4f2e352758 |
| https://git.kernel.org/stable/c/ac31cc837cafb57a271babad8ccffbf733caa076 |
| https://git.kernel.org/stable/c/77de6ee73f54a9a89c0afa0bf4c53b239aa9953a |
| https://git.kernel.org/stable/c/d8e2973029b8b2ce477b564824431f3385c77083 |
