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scsi: target: fix target_cmd_counter leak

PATCH Applied David Disseldorp 3 participants 4 messages Aug 31, 2023 – Sep 14, 2023 SCSI target

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David Disseldorp

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#0 lore raw

PATCH 1/1 scsi: target: fix target_cmd_counter leak

The target_cmd_counter struct allocated via target_alloc_cmd_counter() is never free'd, resulting in leaks across various transport types, e.g.:

unreferenced object 0xffff88801f920120 (size 96):
comm "sh", pid 102, jiffies 4294892535 (age 713.412s) hex dump (first 32 bytes):

    07 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 38 01 92 1f 80 88 ff ff  ........8.......
  backtrace:
    [<00000000e58a6252>] kmalloc_trace+0x11/0x20
    [<0000000043af4b2f>] target_alloc_cmd_counter+0x17/0x90 [target_core_mod]
    [<000000007da2dfa7>] target_setup_session+0x2d/0x140 [target_core_mod]
    [<0000000068feef86>] tcm_loop_tpg_nexus_store+0x19b/0x350 [tcm_loop]
    [<000000006a80e021>] configfs_write_iter+0xb1/0x120
    [<00000000e9f4d860>] vfs_write+0x2e4/0x3c0
    [<000000008143433b>] ksys_write+0x80/0xb0
    [<00000000a7df29b2>] do_syscall_64+0x42/0x90
    [<0000000053f45fb8>] entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Free the structure alongside the corresponding iscsit_conn / se_sess parent.

Signed-off-by David Disseldorp <[email protected]>
---
 drivers/target/target_core_transport.c | 1 +
 1 file changed, 1 insertion(+)
drivers/target/target_core_transport.c +1 -0
index 687adc9e086c..0686882bcbda 100644
@@ -264,6 +264,7 @@ void target_free_cmd_counter(struct target_cmd_counter *cmd_cnt)
 		percpu_ref_put(&cmd_cnt->refcnt);
 
 	percpu_ref_exit(&cmd_cnt->refcnt);
+	kfree(cmd_cnt);
 }
 EXPORT_SYMBOL_GPL(target_free_cmd_counter);
Signature · 1 line
2.35.3
author
#1 lore raw
Quoted 20 lines · David Disseldorp

The target_cmd_counter struct allocated via target_alloc_cmd_counter() is never free'd, resulting in leaks across various transport types, e.g.:

unreferenced object 0xffff88801f920120 (size 96):
comm "sh", pid 102, jiffies 4294892535 (age 713.412s) hex dump (first 32 bytes):

    07 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 38 01 92 1f 80 88 ff ff  ........8.......
  backtrace:
    [<00000000e58a6252>] kmalloc_trace+0x11/0x20
    [<0000000043af4b2f>] target_alloc_cmd_counter+0x17/0x90 [target_core_mod]
    [<000000007da2dfa7>] target_setup_session+0x2d/0x140 [target_core_mod]
    [<0000000068feef86>] tcm_loop_tpg_nexus_store+0x19b/0x350 [tcm_loop]
    [<000000006a80e021>] configfs_write_iter+0xb1/0x120
    [<00000000e9f4d860>] vfs_write+0x2e4/0x3c0
    [<000000008143433b>] ksys_write+0x80/0xb0
    [<00000000a7df29b2>] do_syscall_64+0x42/0x90
    [<0000000053f45fb8>] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Quoted 2 lines

Free the structure alongside the corresponding iscsit_conn / se_sess parent.

I forgot to add...

Fixes becd9be6069e ("scsi: target: Move sess cmd counter to new struct")
Reviewed-by on v1 1/1
#2 lore raw
In reply to David Disseldorp
Quoted 20 lines · David Disseldorp

The target_cmd_counter struct allocated via target_alloc_cmd_counter() is never free'd, resulting in leaks across various transport types, e.g.:

unreferenced object 0xffff88801f920120 (size 96):
comm "sh", pid 102, jiffies 4294892535 (age 713.412s) hex dump (first 32 bytes):

    07 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 38 01 92 1f 80 88 ff ff  ........8.......
  backtrace:
    [<00000000e58a6252>] kmalloc_trace+0x11/0x20
    [<0000000043af4b2f>] target_alloc_cmd_counter+0x17/0x90 [target_core_mod]
    [<000000007da2dfa7>] target_setup_session+0x2d/0x140 [target_core_mod]
    [<0000000068feef86>] tcm_loop_tpg_nexus_store+0x19b/0x350 [tcm_loop]
    [<000000006a80e021>] configfs_write_iter+0xb1/0x120
    [<00000000e9f4d860>] vfs_write+0x2e4/0x3c0
    [<000000008143433b>] ksys_write+0x80/0xb0
    [<00000000a7df29b2>] do_syscall_64+0x42/0x90
    [<0000000053f45fb8>] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Quoted 5 lines

Free the structure alongside the corresponding iscsit_conn / se_sess parent.

Signed-off-by David Disseldorp <[email protected]>

---

Reviewed-by Mike Christie <[email protected]>
Applied
#3 lore raw
In reply to David Disseldorp
Quoted 20 lines · David Disseldorp

The target_cmd_counter struct allocated via target_alloc_cmd_counter() is never free'd, resulting in leaks across various transport types, e.g.:

unreferenced object 0xffff88801f920120 (size 96):
comm "sh", pid 102, jiffies 4294892535 (age 713.412s) hex dump (first 32 bytes):

    07 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 38 01 92 1f 80 88 ff ff  ........8.......
  backtrace:
    [<00000000e58a6252>] kmalloc_trace+0x11/0x20
    [<0000000043af4b2f>] target_alloc_cmd_counter+0x17/0x90 [target_core_mod]
    [<000000007da2dfa7>] target_setup_session+0x2d/0x140 [target_core_mod]
    [<0000000068feef86>] tcm_loop_tpg_nexus_store+0x19b/0x350 [tcm_loop]
    [<000000006a80e021>] configfs_write_iter+0xb1/0x120
    [<00000000e9f4d860>] vfs_write+0x2e4/0x3c0
    [<000000008143433b>] ksys_write+0x80/0xb0
    [<00000000a7df29b2>] do_syscall_64+0x42/0x90
    [<0000000053f45fb8>] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Quoted 1 line

[...]

Applied to 6.6/scsi-fixes, thanks!

[1/1] scsi: target: fix target_cmd_counter leak

      https://git.kernel.org/mkp/scsi/c/d14e3e553e05
Signature · 1 line
Martin K. Petersen	Oracle Linux Engineering