CVE: CVE-2024-35907
Published: 2024-05-19
Description: In the Linux kernel, the following vulnerability has been resolved:

mlxbf_gige: call request_irq() after NAPI initialized

The mlxbf_gige driver encounters a NULL pointer exception in
mlxbf_gige_open() when kdump is enabled.  The sequence to reproduce
the exception is as follows:
a) enable kdump
b) trigger kdump via "echo c > /proc/sysrq-trigger"
c) kdump kernel executes
d) kdump kernel loads mlxbf_gige module
e) the mlxbf_gige module runs its open() as the
   the "oob_net0" interface is brought up
f) mlxbf_gige module will experience an exception
   during its open(), something like:

     Unable to handle kernel NULL pointer dereference at virtual address [PII_REDACTED]
     Mem abort info:
       ESR = 0x[PII_REDACTED]000004
       EC = 0x21: IABT (current EL), IL = 32 bits
       SET = 0, FnV = 0
       EA = 0, S1PTW = 0
       FSC = 0x04: level 0 translation fault
     user pgtable: 4k pages, 48-bit VAs, pgdp=00000000e29a4000
     [[PII_REDACTED]] pgd=[PII_REDACTED], p4d=[PII_REDACTED]
     Internal error: Oops: [PII_REDACTED] [#1] SMP
     CPU: 0 PID: 812 Comm: NetworkManager Tainted: G           OE     5.15.0-1035-bluefield #37-Ubuntu
     Hardware name: https://www.mellanox.com BlueField-3 SmartNIC Main Card/BlueField-3 SmartNIC Main Card, BIOS 4.6.0.13024 Jan 19 2024
     pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
     pc : 0x0
     lr : __napi_poll+0x40/0x230
     sp : ffff800008003e00
     x29: ffff800008003e00 x28: [PII_REDACTED] x27: 00000000ffffffff
     x26: ffff[PII_REDACTED]38 x25: ffff00007cedec00 x24: ffff800008003ec8
     x23:[PII_REDACTED]00012c x22: ffff800008003eb7 x21: [PII_REDACTED]
     x20: [PII_REDACTED] x19: ffff[PII_REDACTED]38 x18: [PII_REDACTED]
     x17: ffff578fcb450000 x16: ffffa870b083c7c0 x15: 0000aaab010441d0
     x14: [PII_REDACTED] x13: 00726f7272655f65 x12: 6769675f6662786c
     x11: [PII_REDACTED] x10: [PII_REDACTED] x9 : ffffa870b0842398
     x8 : [PII_REDACTED] x7 : fe5a48b9069706ea x6 : 17fdb11fc84ae0d2
     x5 : d94a82549d594f35 x4 : [PII_REDACTED] x3 : [PII_REDACTED]
     x2 : [PII_REDACTED] x1 : [PII_REDACTED] x0 : ffff[PII_REDACTED]38
     Call trace:
      0x0
      net_rx_action+0x178/0x360
      __do_softirq+0x15c/0x428
      __irq_exit_rcu+0xac/0xec
      irq_exit+0x18/0x2c
      handle_domain_irq+0x6c/0xa0
      gic_handle_irq+0xec/0x1b0
      call_on_irq_stack+0x20/0x2c
      do_interrupt_handler+0x5c/0x70
      el1_interrupt+0x30/0x50
      el1h_64_irq_handler+0x18/0x2c
      el1h_64_irq+0x7c/0x80
      __setup_irq+0x4c0/0x950
      request_threaded_irq+0xf4/0x1bc
      mlxbf_gige_request_irqs+0x68/0x110 [mlxbf_gige]
      mlxbf_gige_open+0x5c/0x170 [mlxbf_gige]
      __dev_open+0x100/0x220
      __dev_change_flags+0x16c/0x1f0
      dev_change_flags+0x2c/0x70
      do_setlink+0x220/0xa40
      __rtnl_newlink+0x56c/0x8a0
      rtnl_newlink+0x58/0x84
      rtnetlink_rcv_msg+0x138/0x3c4
      netlink_rcv_skb+0x64/0x130
      rtnetlink_rcv+0x20/0x30
      netlink_unicast+0x2ec/0x360
      netlink_sendmsg+0x278/0x490
      __sock_sendmsg+0x5c/0x6c
      ____sys_sendmsg+0x290/0x2d4
      ___sys_sendmsg+0x84/0xd0
      __sys_sendmsg+0x70/0xd0
      __arm64_sys_sendmsg+0x2c/0x40
      invoke_syscall+0x78/0x100
      el0_svc_common.constprop.0+0x54/0x184
      do_el0_svc+0x30/0xac
      el0_svc+0x48/0x160
      el0t_64_sync_handler+0xa4/0x12c
      el0t_64_sync+0x1a4/0x1a8
     Code: bad PC value
     ---[ end trace 7d1c3f3bf9d81885 ]---
     Kernel panic - not syncing: Oops: Fatal exception in interrupt
     Kernel Offset: 0x2870a7a00000 from 0xffff[PII_REDACTED]00
     PHYS_OFFSET: 0x80000000
     CPU features: 0x0,000005c1,a3332a5a
     Memory Limit: none
     ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---

The exception happens because there is a pending RX interrupt before the
call to request_irq(RX IRQ) executes.  Then, the RX IRQ handler fires
immediately after this request_irq() completes. The
---truncated---
CVSS Score: 5.5 (MEDIUM)
CWE: CWE-476
References: https://git.kernel.org/stable/c/24444af5ddf729376b90db0f135fa19973cb5dab; https://git.kernel.org/stable/c/867a2f598af6a645c865d1101b58c5e070c6dd9e; https://git.kernel.org/stable/c/8feb1652afe9c5d019059a55c90f70690dce0f52