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author | Zhihao Cheng <chengzhihao1@huawei.com> | 2023-05-16 22:16:18 +0800 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-03 10:23:47 +0200 |
commit | 53dd2ca2c02fdcfe3aad2345091d371063f97d17 (patch) | |
tree | 8dc8090aff044b59cb5bc50d1953421a9f7aea10 /io_uring | |
parent | a9174f0d7addf4c1c9eddef87d4433b7706e77b7 (diff) | |
download | linux-53dd2ca2c02fdcfe3aad2345091d371063f97d17.tar.gz |
ovl: fix null pointer dereference in ovl_permission()
commit 1a73f5b8f079fd42a544c1600beface50c63af7c upstream. Following process: P1 P2 path_lookupat link_path_walk inode_permission ovl_permission ovl_i_path_real(inode, &realpath) path->dentry = ovl_i_dentry_upper(inode) drop_cache __dentry_kill(ovl_dentry) iput(ovl_inode) ovl_destroy_inode(ovl_inode) dput(oi->__upperdentry) dentry_kill(upperdentry) dentry_unlink_inode upperdentry->d_inode = NULL realinode = d_inode(realpath.dentry) // return NULL inode_permission(realinode) inode->i_sb // NULL pointer dereference , will trigger an null pointer dereference at realinode: [ 335.664979] BUG: kernel NULL pointer dereference, address: 0000000000000002 [ 335.668032] CPU: 0 PID: 2592 Comm: ls Not tainted 6.3.0 [ 335.669956] RIP: 0010:inode_permission+0x33/0x2c0 [ 335.678939] Call Trace: [ 335.679165] <TASK> [ 335.679371] ovl_permission+0xde/0x320 [ 335.679723] inode_permission+0x15e/0x2c0 [ 335.680090] link_path_walk+0x115/0x550 [ 335.680771] path_lookupat.isra.0+0xb2/0x200 [ 335.681170] filename_lookup+0xda/0x240 [ 335.681922] vfs_statx+0xa6/0x1f0 [ 335.682233] vfs_fstatat+0x7b/0xb0 Fetch a reproducer in [Link]. Use the helper ovl_i_path_realinode() to get realinode and then do non-nullptr checking. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217405 Fixes: 4b7791b2e958 ("ovl: handle idmappings in ovl_permission()") Cc: <stable@vger.kernel.org> # v5.19 Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Suggested-by: Christian Brauner <brauner@kernel.org> Suggested-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'io_uring')
0 files changed, 0 insertions, 0 deletions