cbcvebase.
CVE-2024-49868
published 2024-10-21

CVE-2024-49868: In the Linux kernel, the following vulnerability has been resolved: btrfs: fix a NULL pointer dereference when failed to start a new trasacntion [BUG] Syzbot…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.29%
21.0th percentile
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix a NULL pointer dereference when failed to start a new trasacntion [BUG] Syzbot reported a NULL pointer dereference with the following crash: FAULT_INJECTION: forcing a failure. start_transaction+0x830/0x1670 fs/btrfs/transaction.c:676 prepare_to_relocate+0x31f/0x4c0 fs/btrfs/relocation.c:3642 relocate_block_group+0x169/0xd20 fs/btrfs/relocation.c:3678 ... BTRFS info (device loop0): balance: ended with status: -12 Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cc: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000660-0x0000000000000667] RIP: 0010:btrfs_update_reloc_root+0x362/0xa80 fs/btrfs/relocation.c:926 Call Trace: commit_fs_roots+0x2ee/0x720 fs/btrfs/transaction.c:1496 btrfs_commit_transaction+0xfaf/0x3740 fs/btrfs/transaction.c:2430 del_balance_item fs/btrfs/volumes.c:3678 [inline] reset_balance_state+0x25e/0x3c0 fs/btrfs/volumes.c:3742 btrfs_balance+0xead/0x10c0 fs/btrfs/volumes.c:4574 btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f [CAUSE] The allocation failure happens at the start_transaction() inside prepare_to_relocate(), and during the error handling we call unset_reloc_control(), which makes fs_info->balance_ctl to be NULL. Then we continue the error path cleanup in btrfs_balance() by calling reset_balance_state() which will call del_balance_item() to fully delete the balance item in the root tree. However during the small window between set_reloc_contrl() and unset_reloc_control(), we can have a subvolume tree update and created a reloc_root for that subvolume. Then we go into the final btrfs_commit_transaction() of del_balance_item(), and int

Affected

33 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.115-1 (bookworm)linux 6.1.115-1 (bookworm)
debianlinux-6.1< linux 6.1.115-1 (bookworm)linux 6.1.115-1 (bookworm)
linuxlinux
linuxlinux>= 3fd0a5585eb98e074fb9934549c8d85c49756c0d < 1282f001cbf56e5dd6e90a18e205a566793f4be01282f001cbf56e5dd6e90a18e205a566793f4be0
linuxlinux>= 3fd0a5585eb98e074fb9934549c8d85c49756c0d < d73d48acf36f57362df7e4f9d76568168bf5e944d73d48acf36f57362df7e4f9d76568168bf5e944
linuxlinux>= 3fd0a5585eb98e074fb9934549c8d85c49756c0d < 37fee9c220b92c3b7bf22b51c51dde5364e7590b37fee9c220b92c3b7bf22b51c51dde5364e7590b
linuxlinux>= 3fd0a5585eb98e074fb9934549c8d85c49756c0d < d13249c0df7aab885acb149695f82c54c0822a70d13249c0df7aab885acb149695f82c54c0822a70
linuxlinux>= 3fd0a5585eb98e074fb9934549c8d85c49756c0d < 7ad0c5868f2f0418619089513d95230c66cb7eb47ad0c5868f2f0418619089513d95230c66cb7eb4
linuxlinux>= 3fd0a5585eb98e074fb9934549c8d85c49756c0d < dc02c1440705e3451abd1c2c8114a5c1bb188e9fdc02c1440705e3451abd1c2c8114a5c1bb188e9f
linuxlinux>= 3fd0a5585eb98e074fb9934549c8d85c49756c0d < 39356ec0e319ed07627b3a0f402d0608546509e639356ec0e319ed07627b3a0f402d0608546509e6
linuxlinux>= 3fd0a5585eb98e074fb9934549c8d85c49756c0d < c3b47f49e83197e8dffd023ec568403bcdbb774bc3b47f49e83197e8dffd023ec568403bcdbb774b
linuxlinux_kernel< 5.10.2275.10.227
linuxlinux_kernel>= 0 < 5.10.234-15.10.234-1
linuxlinux_kernel>= 0 < 6.1.115-16.1.115-1
linuxlinux_kernel>= 0 < 6.11.4-16.11.4-1
linuxlinux_kernel>= 0 < 6.11.4-16.11.4-1
linuxlinux_kernel>= 0 < 5.4.0-208.2285.4.0-208.228
linuxlinux_kernel>= 0 < 5.15.0-127.1375.15.0-127.137
linuxlinux_kernel>= 0 < 6.8.0-54.566.8.0-54.56
linuxlinux_kernel>= 0 < 6.11.0-18.186.11.0-18.18
linuxlinux_kernel>= 5.11 < 5.15.1685.15.168
linuxlinux_kernel>= 5.16 < 6.1.1136.1.113
linuxlinux_kernel>= 6.11 < 6.11.36.11.3
linuxlinux_kernel>= 6.2 < 6.6.556.6.55
linuxlinux_kernel>= 6.7 < 6.10.146.10.14

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian5.5MEDIUM
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
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