| 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-2021-47353: udf: Fix NULL pointer dereference in udf_symlink function |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| udf: Fix NULL pointer dereference in udf_symlink function |
| |
| In function udf_symlink, epos.bh is assigned with the value returned |
| by udf_tgetblk. The function udf_tgetblk is defined in udf/misc.c |
| and returns the value of sb_getblk function that could be NULL. |
| Then, epos.bh is used without any check, causing a possible |
| NULL pointer dereference when sb_getblk fails. |
| |
| This fix adds a check to validate the value of epos.bh. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47353 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.4.276 with commit 2f3d9ddd32a28803baa547e6274983b67d5e287c |
| Fixed in 4.9.276 with commit 371566f63cbd0bb6fbb25b8fe9d5798268d35af9 |
| Fixed in 4.14.240 with commit baea588a42d675e35daeaddd10fbc9700550bc4d |
| Fixed in 4.19.198 with commit 3638705ecd5ad2785e996f820121c0ad15ce64b5 |
| Fixed in 5.4.133 with commit 80d505aee6398cf8beb72475c7edcf1733c1c68b |
| Fixed in 5.10.51 with commit 21bf1414580c36ffc8d8de043beb3508cf812238 |
| Fixed in 5.12.18 with commit aebed6b19e51a34003d998da5ebb1dfdd2cb1d02 |
| Fixed in 5.13.3 with commit 5150877e4d99f85057a458daac7cd7c01005d5c6 |
| Fixed in 5.14 with commit fa236c2b2d4436d9f19ee4e5d5924e90ffd7bb43 |
| |
| 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-2021-47353 |
| 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: |
| fs/udf/namei.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/2f3d9ddd32a28803baa547e6274983b67d5e287c |
| https://git.kernel.org/stable/c/371566f63cbd0bb6fbb25b8fe9d5798268d35af9 |
| https://git.kernel.org/stable/c/baea588a42d675e35daeaddd10fbc9700550bc4d |
| https://git.kernel.org/stable/c/3638705ecd5ad2785e996f820121c0ad15ce64b5 |
| https://git.kernel.org/stable/c/80d505aee6398cf8beb72475c7edcf1733c1c68b |
| https://git.kernel.org/stable/c/21bf1414580c36ffc8d8de043beb3508cf812238 |
| https://git.kernel.org/stable/c/aebed6b19e51a34003d998da5ebb1dfdd2cb1d02 |
| https://git.kernel.org/stable/c/5150877e4d99f85057a458daac7cd7c01005d5c6 |
| https://git.kernel.org/stable/c/fa236c2b2d4436d9f19ee4e5d5924e90ffd7bb43 |
