CVE-2022-49927

In the Linux kernel, the following vulnerability has been resolved:

nfs4: Fix kmemleak when allocate slot failed

If one of the slot allocate failed, should cleanup all the other allocated slots, otherwise, the allocated slots will leak:

unreferenced object 0xffff8881115aa100 (size 64): comm ""mount.nfs"", pid 679, jiffies 4294744957 (age 115.037s) hex dump (first 32 bytes): 00 cc 19 73 81 88 ff ff 00 a0 5a 11 81 88 ff ff ...s......Z..... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000007a4c434a>] nfs4_find_or_create_slot+0x8e/0x130 [<000000005472a39c>] nfs4_realloc_slot_table+0x23f/0x270 [<00000000cd8ca0eb>] nfs40_init_client+0x4a/0x90 [<00000000128486db>] nfs4_init_client+0xce/0x270 [<000000008d2cacad>] nfs4_set_client+0x1a2/0x2b0 [<000000000e593b52>] nfs4_create_server+0x300/0x5f0 [<00000000e4425dd2>] nfs4_try_get_tree+0x65/0x110 [<00000000d3a6176f>] vfs_get_tree+0x41/0xf0 [<0000000016b5ad4c>] path_mount+0x9b3/0xdd0 [<00000000494cae71>] __x64_sys_mount+0x190/0x1d0 [<000000005d56bdec>] do_syscall_64+0x35/0x80 [<00000000687c9ae4>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Memory Leak in nfs4_setup_slot_table() on Allocation Failure. In NFSv4, if slot allocation fails during the setup of a slot table, previously allocated slots are not freed, leading to a kernel memory leak. The issue occurs during NFS mount attempts and may result in unreferenced kernel memory accumulation (visible via kmemleak). Only local user with ability to invoke mount.nfs (e.g., CAP_SYS_ADMIN) can trigger this one.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.